Note: Descriptions are shown in the official language in which they were submitted.
WO 96/13077 CA 0 2 2 0 2 6 4 5 19 9 7 - 0 4 -14 p~~S94/11908
MODULAR TELECOMMUNICATIONS TERMINAL BLOCK
' BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to terminal blocks for
connecting wire pairs. More particularly, the present
invention relates to telecommunications terminal blocks
for connecting telephone service wires to telephone
exchange distribution cables.
2. Background of the Prior Art and Related Information
Telecommunications terminal blocks are used to
provide convenient electrical connections between
telephone customer service wires (the "service" side) and
telephone exchange distribution cables (the "exchange"
side). Such terminal blocks typically connect up to 25
distribution cable wire pairs on the exchange side, which
may have several thousand wire pairs, to up to 25
individual service wire pairs on the service side.
Terminal blocks generally are configured as
standard, multi-chambered units which terminate either 5,
10 or 25 wire pairs. In many cases the number of
distribution wire pairs to be terminated may not conform
to the standard number. For example, if 7 wire pairs
need to be terminated, a terminal block for 10 wire
pairs, the closest standard terminal block size, must be
installed even through 3 of the 10 wire pair terminations
will not be used.
The exchange side wire pairs are difficult to
replace in that a splicing cable which provides the
connection from the distribution cable to the exchange
side of the terminal block is typically permanently
joined to the terminal block during connection of the
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splice cable to the terminal block. The permanent
connection protects both the splicing cable and the
exchange side of the terminal block from the environment
and ensures a physically secure connection designed to
withstand the recurring installing and removing of
connections on the service side.
When a connection on the exchange side of the
terminal block fails, the entire terminal block of 5, 10
or 25 wire pairs must be replaced, requiring a new
terminal block and significant installation time and
resources. The connection between the splice cable and
the failed terminal block must be physically cut and the
old terminal block discarded, even if only a single
connection has failed on the exchange side. In addition,
in replacing the terminal block, all existing service
side connections must be disconnected. A new terminal
block may then be permanently installed on the splice
cable and all the service side connections connected.
This approach uses significant resources and results in
many terminal blocks being discarded for only a single
failure.
The service side of terminal blocks is generally
subject to the most use because the service side is used
to repeatedly connect or disconnect telephone service to
the distribution cable through the terminal block.
Service wire pairs are typically connected to the
terminal block through some type of terminal which is
easy to connect and disconnect on site such as a simple
binding post where a stripped service wire is connected
to the binding post and then secured with some type of
cap. Another common type of terminal is an insulation
displacement terminal where the service wire need not be
bared prior to the connection to the terminal block and
the insulation is severed through a blade or other sharp
i
surface as the service wire is secured to the terminal.
Again, in the insulation displacement type of terminal,
some type of cap is typically employed to secure the
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service wire in place.
While the caps typically employed in the binding
post or insulation displacement type terminals provide
some protection from the environment, nonetheless,
moisture, pollutants, chemicals, dust and even insects
may reach the terminal connection resulting in corrosion
or other degradation of the contact. This problem is
exacerbated by the -fact that in addition to the
traditional aerial location of such terminal blocks,
underground and even underwater terminal block locations
are more and more frequently required for telephone
distribution applications. Accordingly, efforts have
been made to better insulate the terminal in the terminal
block from the environment to prevent such degradation.
One such approach has been to use a variety of insulating
mediums, such as greases or gels to surround the terminal
where the electrical connection is made.
In order to properly test connections and determine
if a problem is related to the exchange side or the
service side is it necessary to disconnect one side so
that either side may be evaluated independently.
Generally, the service side is disconnected because it
may not be possible to disconnect the exchange side
wires. In this case, additional time is spent
disconnecting the service side wires, stripping the
wires, and connecting the wires to test equipment to
assess the problem. Once the problem is solved, the test
assembly must be removed and the service side wires
connected to the terminal block. This process requires
significant time.
Accordingly, a need presently exists for an improved
telecommunications terminal block for connecting wires
from the exchange side to the service side such that
individual terminal blocks may be added or removed as
required while maintaining resistance to moisture and
other environmental factors which subject the connections
therein to degradation over time and limit the
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applications where such terminal blocks may be reliably
employed. In addition, a need presently exists for an
improved telecommunications terminal block for which ,
permits testing of the service or exchange sides without
disconnecting service or exchange side wires. ,
SUMMARY OF THE INVENTION
The present invention provides a modular
telecommunications terminal block system including a
variable number of individual terminal blocks for
connecting service wires to a telephone exchange cable
such that individual terminal blocks may be added or
removed as required while maintaining an insulating
medium within each terminal block. This medium, which
may be a grease or gel, provides resistance to moisture
and other environmental factors which subject the
connections therein to degradation over time.
In a preferred embodiment, each of the individual
terminal blocks of the modular telecommunications
terminal block of the present invention employs a
separate housing formed of a dielectric material. Each
individual terminal block is attached to a mounting rail
and held in place, for example, by a pliable clip
integrally formed with the housing. Each housing forms
a separate receptacle for the insulating medium which
flows within chambers in the housing during wire
connection and disconnection.
Connection to the exchange cable wires is provided
via an exchange wire carrier movable relative to the
housing and configured on an exchange side of the
housing. Connection to service wires in turn is provided
by a service wire carrier movably conf figured in a chamber
within the housing, accessible from an opposite service
side of the housing.
More specifically, a pair of exchange wire access
slots are provided on the housing to receive a pair of
exchange wires. Within a chamber in the housing,
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proximate the exchange wire access slots, is located the
exchange wire carrier. The exchange wire carrier is
movable between an open position and a closed position
and receives each of the exchange wires into respective
exchange wire conduits. The exchange wire carrier is
held i.n place in the selected position by a retaining
stub which slides into either of two retaining stub slots
in the housing which correspond to the chosen position,
open or closed, of the exchange wire carrier.
When the exchange wire carrier is in the open
position, the exchange wire conduits may receive each
exchange wire through the exchange wire access slots in
the housing. The exchange wire carrier has two slots for
receiving insulation piercing electrical contact blades.
The insulation piercing contact blades are integrally
formed with an exchange wire junction contact which is
retained in a slot in the access jack.
The terminal block may be easily mounted on the
mounting rail by hooking a lip configured proximate the
service end of the terminal block over an edge of the
mounting rail. The exchange end of the terminal block is
then pushed into place over the other edge of the
mounting rail until a pliable clip integral to the
housing snaps into place. Therefore each end of the
terminal block is secured to the mounting rail.
As the exchange side is pushed onto the mounting
rail, the exchange wire carrier is forced upward by the
pressure from the mounting rail and is moved into the
closed position. When the exchange wire carrier is moved
to the closed position, the insulation piercing contact
blades pierce the insulation of the exchange wires and
come into contact with the conductive portion of the
exchange wires. As a result, the exchange wires are in
conductive contact with the exchange wire junction
contact in a slot in the access jack.
Once installed on the mounting rail, service wires
may be terminated at the service side of the terminal
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block. Upon termination, each service wire is in
conductive communication with a service wire junction
contact retained within a slot in the access jack. A ,
linking module is inserted into the access jack which has
two sets of contacts which form a conductive path between
each service wire and corresponding exchange wire. Each
set of contacts may be accessed through "tee-in" ports on
the top of the linking module.
The linking module may include many types of plug-in
units including a bridge module which simply connects the
service side to the exchange side. Another embodiment
includes a protector module which connects the service
and exchange sides when plugged into the access jack and
includes a twin gas discharge tube and an earth junction
contact. Each end of the twin gas discharge tube is
soldered to one set of contacts and the earth junction
contact is conductively connected to the center of the
gas discharge tube.
The another embodiment of the linking module is the
two-way testing module. The two way testing module
includes a set of service wire testing contacts and a set
of exchange wire testing contacts. The cover of the two
way testing module includes a bayonet contact. The
service wire and exchange wire testing contacts are each
formed with a slot which retains the bayonet contact and
which connects the service side to the exchange side when
the bayonet contact is inserted. The bayonet contact is
automatically inserted into the testing contacts when the
cover of the two-way testing module is closed.
Therefore, when the cover is closed the exchange side is
connected to the service side. The two-way testing
module is sealed with a gasket when the lid is closed.
The gasket provides the internal components of the gasket
with protection from the environment.
When the cover is open the exchange side is no
longer connected to the service side and the ends of the
service wire testing contacts and the exchange wire
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testing contacts are exposed above the gasket so that an
alligator-type or equivalent test connector can be
conveniently connected to either the service wire test
contacts or the exchange wire test contacts for testing.
Another embodiment of the two-way testing module
includes a protected two-way testing module which
connects the service and exchange sides when plugged into
the access jack and includes a twin gas discharge tube
and an earth junction contact. Each end of the twin gas
discharge tube is soldered to one set of contacts and
the
earth junction contact is conductively connected to the
center of the gas discharge tube.
When either the protector module or the protected
two-way testing module is to be used, the earth junction
contact needs to be at earth potential. To achieve this,
the mounting rail is connected to earth during
installation. The mounting rail thus provides the
necessary earth connection point for each terminal block.
When the terminal block is installed on the mounting rail
a terminal block earth connector retained within the
exchange wire carrier is connected to the mounting rail
earth connector. The terminal block earth connector is
conductively connected to an earth junction contact
retained in the central slot of the access jack.
Therefore, when the protector module is plugged into the
access jack, the earth junction contact enters the center
slot of the access j ack and connects the protector module
to earth through the mounting rail. Among its many
functions, the gas discharge tube and earth junction
contact connection perform in conjunction with the two
sets of contacts to shunt voltage to earth in the event
there are voltage spikes on the conductive path between
1
the service side and the exchange side, for example.
Room is provided in the exchange wire carrier, the
chamber containing the service wire carrier and the
linking module for the insulating medium, such as a
grease or gel, to be injected so as to surround each wire
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carrier and set of contacts and fill the wire engaging
openings in the carriers. The medium flows around the
respective carriers during wire termination without ,
forcing medium out of the housing.
The service wires may be removed and reconnected
through the service side openings and the service wire
carrier numerous times.
The terminal block may be installed and removed from
the mounting rail as many times as needed while retaining
the insulating medium therein. Removal from the mounting
rail is accomplished by lifting the clip and releasing
the terminal block from the mounting rail. No
specialized tools are required. Once removed, the
exchange wire carrier may be moved back into the open
position in order to remove the exchange wires. Upon
removal, the terminal block may be reused.
A reliable, easy to manufacture structure is a
further feature of the terminal block of the present
invention. Further features and advantages of the
present invention will be appreciated by review of the
following detailed description of the present invention.
Accordingly, it will be appreciated that the present
invention provides an improved telecommunications
terminal block having significantly improved resistance
to environmental factors such as moisture, chemicals and
other such contaminants while retaining a relatively
simple construction.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a service side of
a preferred embodiment of the modular terminal block
system of the present invention.
Figure 2 is a perspective view of an exchange side
of a preferred embodiment of a plurality of the modular
- 35 terminal block system of the present invention showing a
pair of exchange side wires connected to one terminal
block.
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Figure 3 is an exploded view of the basic components
of the terminal block housing including a service side
~ wire carrier and an exchange side wire carrier of the
present invention.
. 5 Figure 4 is an exploded view illustrating the
housing and the housing insert of a terminal block in
accordance with the present invention.
Figure 5 is a broken away view showing an interior
of a terminal block in accordance with the present
invention, illustrating an exchange side wire carrier
position before terminating an exchange wire and a
service side wire carrier position before terminating a
service wire.
Figure 6 is a broken away view showing an interior
of a terminal block in accordance with the present
invention, illustrating an exchange side wire carrier
position after terminating an exchange wire and a service
side wire carrier position after terminating a service
wire.
Figure 7 shows a cut-away view taken along line 7-7
of Figure 6 showing a cross-section of an actuator and
the service side wire carrier in accordance with the
present invention.
Figure 8 shows a cut-away view taken along line 8-8
of Figure 6 showing a cross-section of the exchange side
wire carrier in accordance with the present invention.
Figure 9 shows a perspective view of the detail of
an earth connection between a terminal block and the
mounting rail in accordance with the present invention.
Figure 10 shows a bottom view of the detail of the
earth connection between the terminal block and the
mounting rail.
Figure 11 is an exploded view of the basic
components of the protector module in accordance with an
alternate embodiment of the present invention.
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Figure 12 is an exploded view of the basic
components of the two-way testing module in accordance
with an alternate embodiment of the present invention.
Figure 13 is a broken away view showing an interior
of a two-way testing module in accordance with an
alternate embodiment of the present invention.
Figure 14 shows a cut-away view taken along line 14
14 of Figure 13 showing a cross-section of a two-way
testing module in accordance with an alternate embodiment
of the present invention.
Figure 15 is an exploded view of the basic
components of the protected two-way testing module in
accordance with an alternate embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Figure 1, the modular terminal block
system of the present invention is illustrated. As
shown, in a preferred embodiment of the present invention
a number of individual terminal blocks is employed, which
number may vary from 1 to 25 or more with the specific
application. One of the terminal blocks is shown as
removed from the mounting rail.
Each terminal block 10 of the modular system of the
present invention employs a separate terminal block
housing 12. The service side of the terminal block is
illustrated and has service wire pair openings 14 along
a front surface thereof. As will be discussed in more
detail below, the wire pair openings 14 provide service
wires access into an internal chamber within the housing
12. Housing 12 is composed of a dielectric material,
suitable for manufacture in the desired shape. For ,
example, any one of several commercially available
thermoplastic resins may be readily employed due to their ,
relatively low cost and ease of manufacture. Other
dielectric materials may be also employed, however.
As illustrated in Figures 1, 3 and 4, a portion of
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the bottom of the terminal block 10 of the present
invention includes an exchange wire carrier 20. The
exchange wire carrier 20 is preferably made of a
dielectric material which may be the same as housing 12.
The exchange wire carrier also includes an earth
connector guide 22 which protrudes down from the base of
the exchange wire carrier 20.
The earth connector guide 22, best shown in Figures
3, 4 and 10, supports an earth connector 18 which
connects to the mounting rail 24 in a manner as
illustrated in Figures 9 and 10. The terminal block is
mounted on a standard DIN mounting rail 24 modified to
include the rail earth connector 26 which is tied to
"earth" by connecting the conducting mounting rail 24 to
earth upon installation. The mounting rail 24 may be
manufactured from steel or aluminum or any other suitably
conductive material. Earth connector 18, supported by
the earth connector guide 22, provides the conductive
connection to the rail earth connector 26. Figure 9
illustrates a perspective view of the detail of the earth
connector guide 22 and the earth connector 18 before
connecting to the mounting rail 24 at the rail earth
connector 26. Figure 10 illustrates a bottom view
showing the earth connector guide 22 and earth connector
18 connected to the mounting rail 24 at the rail earth
connector 26.
As illustrated in Figure 1, the terminal block 10 is
secured to the mounting rail by front lip 28, located
proximate the service side of the terminal block, rear
clip 30, located proximate the exchange side of the
terminal block, and earth connector guide 22. Front lip
28 has an inner ledge which secures the front of the
terminal block by capturing the mounting rail between
itself and the bottom structure of the terminal block. '
Rear clip 30 provides an inner ledge which secures the
rear of the terminal block to the mounting rail 24.
Terminal block earth connector guide 22 (as illustrated
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in Figure 9) and rail earth connector 26 guide the
terminal block onto the mounting rail 24. The terminal
block is secured to the mounting rail by first securing
the front clip 28 to the mounting rail. Once terminal
block earth connector 18 and earth connector guide 22
have been properly aligned with rail earth connector 26,
downward pressure is applied to the rear portion of the
terminal block to urge the rear clip 30 over the edge of
the mounting rail until the rear clip engages the
mounting rail--snapping the terminal block firmly in
place. The earth connection is made as the terminal
block snaps into place.
Depending on the application of the terminal block,
the mounting may include only the front lip 28 and the
rear clip 30, in those applications where an earth
connection is not required. In addition, the use of
alternate mounting apparatus are contemplated instead of
the clip and lip combination such as fastening the
terminal block to the mounting rail using a clipping
mechanism at both ends of the terminal block; fastening
the terminal block by reversing the locations of the clip
and the lip at the ends of the terminal block; or,
fastening the terminal block to the mounting rail using
an industrial hook and eye fastener such as VELCRO.
In order to remove the terminal block 10 of the
present invention from the mounting rail 24, any flat
ended tool such as a screwdriver may be used to apply
force, prying the rear clip 30 away from the mounting
rail 24, such that the rear clip 30 may be disengaged
from the mounting rail 24 and the entire terminal block
released from the mounting rail.
In this manner any number of terminal blocks may be ,
ganged together along a mounting rail to provide access
to additional service wires from a splice cable secured
to an exchange distribution cable, as required. In this
embodiment, a single terminal block would be provided for
each exchange wire pair and service wire pair. Depending
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on the configuration, a single mounting rail may be used
or multiple mounting rails may be used. The terminal
~ blocks may be snapped into place along the mounting rail
24 or removed to alter the number of terminal blocks as
needed. In addition, as will be discussed in more detail
below, the exchange side wires of the terminal block and
the service side wires of the terminal block may be
repeatedly connected and disconnected.
Also, for other types of applications, a single
service wire opening instead of a pair of openings 12 may
be employed for each terminal block, or additional
service wire openings could be provided into each
terminal block if a need arose in a specific application.
Accordingly, the configuration of service wire openings
and their configuration on the mounting rail 24 is an
illustrative preferred embodiment only and may be varied
with the specific application as needed.
Still referring to Figure 1, the top of each housing
12 includes a terminal actuator 32. As will be discussed
in more detail below, the remainder of the actuator 32
extends through the housing 12 into the service side
internal chamber. As illustrated in Figure 1 by the
position where terminal actuator 32 has been omitted for
illustration, the actuator 32 protrudes from the interior
of the housing 12 through opening 34 in housing 12.
Terminal actuator 32 is preferably made of a dielectric
material which may be the same as housing 12. The top of
the terminal actuator 3 2 pref erably has a shape which may
be readily engaged and turned by a hand held screw
driver, wrench or other implement. Alternatively,
actuator 32 may be adapted to be grasped and turned by a
user of the terminal block. Turning the actuator a fixed
amount, preferably indicated by visual markings on the
housing and actuator, effects the connection of the
-service wires to the exchange wires in a manner to be
discussed in more detail below.
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Referring to Figure 2, a plurality of a preferred
embodiment of the terminal block of the present
invention, showing the exchange side, are illustrated.
The terminal block 10 of the present invention employs a
terminal block housing 12 having exchange wire pair
openings 36 along a rear surface thereof. As will be
discussed in more detail below, the exchange wire pair
openings 36 provide exchange wires with access into an
internal chamber within housing 12.
Also, for other types of applications, a single
exchange wire opening instead of a pair of openings 36
may be employed for each terminal block, or additional
exchange wire openings could be provided into each
terminal block if a need arose in a specific application.
Accordingly, the configuration of exchange wire openings
and their configuration on the mounting rail 24 is an
illustrative preferred embodiment only and may be varied
with the specific application as needed.
As further illustrated in Figure 2, the terminal
block 10 includes a linking module 16 which has a cap 42
with two "tee-in" test ports 44 (as shown in Figure 1).
As will be discussed in more detail below, the linking
module 16 provides the connection between the service
side and the exchange side of the terminal block and may
be embodied in a number of configurations. Preferably
the linking module includes a basic configuration
referred to herein as a bridge module having contacts
(shown in Figure 4) which provide a connection between
the service side wires and exchange side wires. An
alternate embodiment of the linking module, referred to
herein as a protector module, protects the service and
exchange wires from voltage spikes. Both the bridge
module and the protector module provide test ports 44 to
allow testing of the service and exchange sides without -
opening the terminal block or disconnecting the service
or exchange side wires.
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Referring to Figure 3 , an exploded view of the basic
components of a terminal block housing including the
a exchange side wire carrier and the service side wire
carrier of the present invention is illustrated. The
terminal block of the present invention includes a path
for each of two wire connections between the exchange
side and the service side. To simplify the description,
and to avoid unnecessarily cluttering the drawings, only
those components defining a single conductive path
through the terminal block are described, although the
detailed description applies equally to both conductive
paths.
As illustrated, the exchange wire carrier 20
includes an exchange wire conduit 92 which carries the
exchange wire after the exchange wire has been inserted
into one of the exchange wire pair openings 36 (as
illustrated in Figure 2). The exchange'wire carrier 20
includes a contact blade receiving slot 94, for receiving
the exchange wire contact blade (as described below) and
earth connector receiving slot 98 which terminates at
the
earth connector guide 22 and which receives the earth
connector (not shown).
A service wire carrier 50 is provided which is
threadedly engaged with the terminal actuator 32. More
particularly, the service wire carrier 50 has a threaded
opening 34 in the top end thereof for receiving the
matching size threaded end of terminal actuator 32. The
terminal actuator 32 includes a plug 54 used to retain
the insulating media within housing 12 as will be
described later. The service wire carrier 50 also has
a
wire receiving opening 56 for receiving a service wire
inserted into the housing. The wire receiving opening
56
is sealed with a perforated seal 58 intended to retain
the insulating media within housing 12 as will be
described below.
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Each wire receiving opening 56 extends through a
flanged extension 60 of the service wire carrier 50 into
the central portion of the carrier 50. A first contact
blade receiving slot 62 is provided in the carrier at a
first position along opening 56 and a second contact _
blade receiving slot 64 is provided at a second position
along opening 56. The first and second contact blade
receiving slots 62, 64, respectively, receive first and
second insulation cutting contact blades 66, 68. The
service wire carrier 50, including the first and second
insulation cutting contact blades 66, 68 is retained
within the terminal block housing insert 70.
Housing insert 70 includes first and second contact
blade retaining slots 72, 74, respectively, for each set
of contact blades. The first and second contact blade
retaining slots receive first and second insulation
cutting contact blades 66, 68. Housing insert 70 also
retains the service wire junction contact 76. Each
service wire junction contact 76 is integrally formed
with the first and second insulation cutting contact
blades 66, 68. Therefore, when either of the insulation
cutting contact blades 66, 68 is in conductive
communication with a service wire, it is also in
conductive communication with the corresponding service
wire junction contact 76.
As illustrated in Figure 4, the housing insert 70
retains the exchange wire junction contact 80 and earth
junction contact 84 in addition to junction contact 76.
These junction contacts are inserted into the base of the
five-prong access jack 120 when the housing insert is
placed into the housing 12. More particularly, the
service wire junction contact 76 is retained within ,
service wire junction contact slot 122 and the exchange
wire junction contact 80 is retained within the exchange .
wire junction contact slot 124. Earth junction contact
84 is retained within the centrally situated earth
junction contact slot 130.
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As illustrated in Figure 4, the exchange wire
carrier 20 is inserted into a space formed between the
- housing 12 and the housing insert 70 into the housing
12.
Upon insertion, the exchange wire contact blade receiving
- 5 slot 94, receives the exchange wire insulation cutting
contact blade 170. The insulation cutting contact blade
170 is integrally formed with the exchange wire junction
contact 80 and of a metallic conductor to provide good
electrical contact from the junction contact 80 to the
exchange wire when the insulation cutting contact blade
170 pierces the insulation thereof during termination
as
described below.
As illustrated in Figure 4, the terminal block of
the present invention includes a bridge module 40
embodiment of the linking module. The bridge module 40
includes a path for each of two wire connections between
the exchange side and the service side. To simplify the
description, and to avoid unnecessarily cluttering the
drawings, only those components defining a single
conductive path through the bridge module are described,
although the detailed description applies equally to both
conductive paths.
The bridge module 40 includes a set of integrally
formed bridge contacts 110. Each set of bridge contacts
110 includes a service wire junction contact 114 and an
exchange wire junction contact 116. The contacts are
maintained within the bridge module with a hard
encapsulant such as a non-conductive epoxy, the top
surface of which is illustrated as encapsulant 38. The
hard encapsulant only occupies a portion of the interior
of the bridge module 40. The remainder of the interior
of the bridge module 40, comprising approximately the
top
third of the interior of the bridge module 40, is filled
with an insulating gel. Therefore a test probe may be
inserted into tee-in test port 44 to make conductive
contact with the set of bridge contacts 110.
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Figure 4 also illustrates the gasket 118 which is
used to provide a seal between the selected linking
module and the five-prong access jack 120 of the housing ,
12. The gasket is constructed of an elastic material
known in the art and capable of serving as an _
environmental barrier between the five-prong access jack
120 and the external environment. The gasket provides a
seal such that once the linking module is snapped into
place over the five-prong access jack 120, no
environmental contaminants or moisture may enter the
junction contact area.
As best illustrated in Figures 5, 6 and 8,
installation of an exchange wire on the exchange side is
illustrated. Figure 5 shows a broken away view showing
an interior of the terminal block of the present
invention illustrating the exchange side wire carrier
position before terminating an exchange wire. In regard
to the installation of the exchange side wire, an
internal exchange side chamber 160 is preferably formed
with the bottom and rear of housing insert 70, sides and
rear of housing 12 and top of exchange wire carrier 20.
The exchange wire carrier 20 is retained in place within
the chamber through the combined action of the exchange
wire carrier retaining stub 176 (as shown in Figure 3) in
correspondence with first or second exchange wire carrier
retaining slots 178, 180. The exchange wire carrier 20
may be moved into an open or closed position by exchange
wire carrier actuator slot 164 which is integrally formed
with the exchange wire carrier 20. The actuator slot 164
may be manipulated by a simple tool such as a screwdriver
to push the exchange wire carrier away from the roof of
the housing 12 into the open position, as shown in Figure ,
5, thus opening the exchange wire chamber 160. In the
open position the exchange wire carrier is retained by .
the exchange wire carrier retaining stub 176 and exchange
wire carrier retaining slot 178.
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Once the exchange wire carrier 20 is moved into the
open position, the exchange wire 162 may enter the
exchange wire opening 36 in the housing 12 and travel
into the exchange wire receiving opening 166 in the
exchange wire carrier 20 and finally into the exchange
wire receiving opening 168 of the housing insert 70 until
seated at the base of the opening. Preferably, if both
conductive paths are to be used, both exchange side wires
are inserted into the exchange side wire carrier before
the terminal block is snapped into place on the mounting
rail.
Figure 6 shows a broken away view of the interior of
the terminal block of the present invention, illustrating
the exchange side wire carrier position after terminating
an exchange wire. Figure 8 shows a second view which is
a cross-section of the exchange side wire carrier after
terminating an exchange wire taken along line 8-8 of
Figure 6. The exchange wire may be terminated, as
illustrated, when the terminal block 10 is snapped into
place onto the mounting rail 24. Installing the terminal
block 10 onto the mounting rail forces the exchange wire
carrier 20 upwards, into the closed position. In pushing
the exchange wire carrier upwards, the exchange wire
carrier retaining stub 176 is forced out of exchange wire
carrier retaining slot 178 and into exchange wire carrier
retaining slot 180. The exchange wire may also be
terminated by pushing the exchange wire carrier into the
closed position manually and then installing the terminal
block onto the mounting rail.
In closing the exchange wire carrier, the exchange
wire is put in conductive communication with the exchange
< wire junction contact 80 as follows. The exchange wire
162 is seated in the exchange wire conduit 92. As the
. exchange wire carrier is forced upwards into the closed
position, the exchange wire insulation cutting contact
blade 170 is forced into the exchange wire 162 while
traveling into the exchange wire contact blade receiving
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slot 94. The insulation cutting contact blade 170 cuts
through the exchange wire insulation and makes contact
with the metallic conductor of the wire. The exchange r
wire junction contact 80 is simultaneously put in
conductive communication with the exchange wire because -
it is in conductive communication with the insulation
cutting contact blade 170.
Figures 5, 6 and 7 illustrate installation of a
service wire on the service side. As best illustrated in
Figure 5, a broken away view showing an interior of the
terminal block of the present invention illustrates the
service side wire carrier position before terminating a
service wire. As illustrated, an internal service side
chamber 150 is preferably integrally formed with the tops
and sides of housing 12 and the top of housing insert 70.
The service wire carrier 50 is opened by turning the
terminal actuator 32 until the service wire carrier 50
has been fully retracted towards the roof of the housing
12. Once the service wire carrier 50 has been retracted
into the open position, the service side wire 152 may
enter the perforated seal 58 and travel into the service
wire receiving opening 56 until seated at the base of the
opening. In practice both service side wires are
inserted into the service side wire carrier before
terminal actuator 32 is used to terminate the wires.
Figure 6 illustrates the service side wire carrier
position after terminating a service wire and Figure 7
shows a second view which is a cross-section of the
terminal actuator and the service side wire carrier after
terminating a service wire taken along line 7-7 of Figure
6. As illustrated, the first and second contact blade
receiving slots 62, 64, respectively, receive first and
second insulation cutting contact blades 66, 68, when the
service wire carrier 50 is in the closed position. The
first and second insulation cutting contact blades 66, 68
are each integrally formed with a service wire junction
contact 76 and are formed of a metallic conductor to
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provide good electrical contact from the service wire
junction contact 76 to the service wire when blades 66,
68 pierce the insulation thereof. Therefore, once an
insulation cutting contact blade is in conductive
- 5 communication with a service wire, it is also in
conductive communication with the corresponding service
wire junction contact 76.
Which of the two blades 66, 68 makes electrical
contact to the wires is determined by the diameter of
the
wire. That is, whether the wire is inserted to the first
slot 62 or second slot 64 will depend on the wire
diameter. For example, as illustrated in Figure 6, a
large gauge wire will only proceed along opening 56 far
enough to reach slot 62 and will thus make electrical
contact with blade 66. A smaller gauge wire in turn will
reach to second slot 64 and make contact with the second,
longer blade 68.
As best illustrated in Figure 6, the top portion of
housing 12 over the chamber 150 is provided with an
annular groove 154 around opening 34. The top end of
terminal actuator 32 is provided with a matching annular
flange 156 which fits within the annular groove 154.
This thus prevents vertical motion of the terminal
actuator 32 during rotation thereof, in contrast to prior
art actuator type connectors which screw down into a
receptacle to make contact with a service wire.
As best illustrated in Figure 4, once the exchange
and service wires have been terminated as described in
Figures 5-8, the exchange wire is conductively connected
to exchange wire junction contact 80 at exchange wire
junction contact slot 124 in the five-prong access jack
120. The service wire is conductively connected to
service wire junction contact 76 at service wire junction
contact slot 122 in the five-prong access jack 120. The
earth connector 18 is conductively connected to the earth
junction contact 84 at earth junction contact slot 130.
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In order to conductively connect the service side to
the exchange side using the bridge module 40, the bridge
module 40 is plugged into the five-prong access jack 120. .
The set of bridge contacts 110 complete the conductive
loop between the exchange side and the service side.
Once connected, the tee-in test port 44 (as shown in
Figure 2) may be used to perform diagnostic testing with
which to examine the signal provided by the connection.
In the alternative, the bridge module may be removed
and replaced with a protector module 140 as illustrated
in Figure 11. The protector module 140 performs the same
function as bridge module 40, in terms of connecting the
service and exchange sides when plugged into the five
prong access jack 120, but also includes a gas discharge
tube 142 and an earth junction contact 144. The gas
discharge tube 142 has three conductive rings, one ring
146 encircling the circumference of each of the ends of
the tube and a third ring 148 encircling the middle of
the tube. Each of the rings is soldered or conductively
secured to a contact. Therefore, each set of contacts
110 are conductively connected to the end rings,
respectively, and the earth junction contact 144 is
conductively connected to the middle ring. Among its
many functions, the gas discharge tube 142 and earth
junction contact connection 144 perform in conjunction
with contacts 110 to shunt voltage to earth in the event
there are voltage spikes on the conductive path, for
example. Therefore, once the protector module is plugged
into the five-prong access jack 120, the two primary
conductive paths between the exchange side and the
service side are protected from intermittent destructive
voltage levels. The use and operation of the gas ,
discharge tube and its application in protecting signal
lines in this manner are well known in the art.
As in the bridge module 40 of the present invention,
the contacts 110 and the gas discharge tube 142 within
the protector module 140 are maintained within the
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protector module with a hard encapsulant such as a non-
conductive epoxy. The hard encapsulant only occupies a
portion of the interior of the protector module 140, as
used in the bridge module. The remaining top third of
the interior of the protector module 140 is filled with
an insulating media. Therefore a test probe may be
inserted into tee-in test port 44 to make conductive
contact with the set of contacts 110 to perform
diagnostic tests on the connection. The bridge module 40
and the protector module 140 may be used interchangeably
with the housing 12, and the five-prong access jack 120,
depending on the application desired by the user.
In the alternative, the bridge module may be removed
and replaced with a two-way testing module 200 as
illustrated in Figure 12. The two-way testing module
performs the same function as the bridge module 40, in
terms of connecting the service and exchange sides when
plugged into the five-prong access j ack 12 0 , but includes
a configuration of the contacts which permits testing
either the exchange side or the service side without
disconnecting the exchange side or service side wires.
The two-way testing module also includes a protected
embodiment which is further described below.
The two-way testing module 200 includes a path for
each of two wire connections between the exchange side
and the service side. To simplify the description, and
to avoid unnecessarily cluttering the drawings, only
those components defining a single conductive path
through the two-way testing module are described,
although the detailed description applies equally to both
conductive paths.
The two-way testing module 200 includes a housing
202 and a hinged cover 204. The testing module housing
_ _ 202 and cover 204 are-preferably made of a dielectric
material which may be the same as housing 12 (as
illustrated in Figure 1). The hinges 206 are integrally
formed with cover 204 so that hinges and cover comprise
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a single unit. The hinged cover 204 is rotatably secured
to the housing by pins 208 which are integrally formed
with the housing. The hinged cover 204 includes bayonet
contacts 210 which are secured perpendicular to the
interior of the hinged cover and formed of a metallic, -
conductive material such as brass, although other
sufficiently conductive materials would perform
adequately.
Within housing 202 are secured two sets of test
contacts. Each set of test contacts includes a service
wire test contact 214 and an exchange wire test contact
216. Each contact is formed of a metallic, conductive
material similar to that of the bayonet contact 210.
Each contact has a plurality of bends. One set of bends
create an area 218 into which a twin gas discharge tube
may be inserted for a protected embodiment of the two-way
testing module (described further below). A second set
of bends 220 are provided in correspondence with a slot
222 in each contact which permits the insertion of the
bayonet contact 210 simultaneously into the service wire
test contact 214 and the exchange wire test contact 216.
The top end of the service wire test contact 214 and the
exchange wire test contact 216, proximate the cover 204,
conclude in a lip 224 which provides a convenient grip
with which to affix an alligator-type test lead, or other
similar test lead, for testing of either the service side
or the exchange side.
Figure 13 is a broken away view showing an interior
of a two-way testing module. Figure 14 shows a cut-away
view taken along line 14-14 of Figure 13 showing a cross
section of the two-way testing module 200. As
illustrated in Figure 13, the contacts are maintained
within the two-way testing module 200 with a hard
encapsulant such as a non-conductive epoxy, the top _
surface of which is illustrated as encapsulant 230. The
hard encapsulant occupies a portion of the interior of
the two-way testing module 200. The remainder of the
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interior of the two-way testing module 200 is sealed by
gasket 232. The gasket is secured to the top edge of the
housing 202. When the cover 204 is closed, the gasket
232 provides a seal between the cover 204 and the housing
- 5 202 such that an environmental seal is formed which
protects the contents of the two-way testing module from
the environment. More particularly, the gasket 232
provides an environmental shield which protects the
junction between the service wire test contact 214, the
exchange wire test contact 216 and the bayonet contact
210. Therefore the connection between the service side
and the exchange side, formed when the cover is closed
and the bayonet contact is inserted into the slot 222
provided in the service wire test contact 214 and the
exchange wire test contact 216, is protected from the
environment by the gasket. Preferably, the interstitial
space between the encapsulant and the gasket is filled
with an insulating media which further protects the
junction from the environment.
As illustrated in Figure 13, the cover 204 may be
pried open with the help of any flat tool such as a
screwdriver. Once opened, a lip 224 located on the top
of each contact, is exposed above the gasket 232 so that
an alligator-type or equivalent test connector can be
conveniently connected to either the service wire test
contact 214 or the exchange wire test contact 216 for
testing. Even when the two-way testing module is in the
open position the contents of the module below the gasket
are substantially protected from the environment because
only the two slots normally filled with the bayonet
contacts are open.
The cover may be provided with a tee-in test port
44. Therefore, a test probe may be inserted into the
_ tee-in test port 44 to make conductive contact with the
service and exchange sides once they are connected by the
bayonet contact, without opening the two-way testing
module cover.
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In the alternative, the two-way testing module 200
may be removed and replaced with a protected two-way
testing module 240 as illustrated in Figure 15. The
protected two-way testing module 240 performs the same
function as two-way testing module 200, in terms of .
connecting the service and exchange sides when plugged
into the five-prong access jack 120, but also includes a
gas discharge tube 142 and an earth junction contact 144,
which perform substantially as described in association
with Figure 1l.
The gas discharge tube 142 has three conductive
rings, one ring 146 encircling the circumference of each
of the ends of the tube and a third ring 148 encircling
the middle of the tube. Each of the rings is soldered or
conductively secured to a contact. Therefore, in one
embodiment, the exchange wire test contacts 216 are
conductively connected to the end rings, respectively,
and the earth junction contact 144 is conductively
connected to the middle ring 148. In the alternative,
the service wire test contacts 214 are conductively
connected to the end rings, respectively, and the earth
junction contact 144 is conductively connected to the
middle ring. Therefore, once the protected two-way
testing module is plugged into the f ive-prong access j ack
120, and cover 204 is in the closed position, the two
primary conductive paths between the exchange side and
the service side are protected from intermittent
destructive voltage levels. The use and operation of the
gas discharge tube and its application in protecting
signal lines in this manner are well known in the art.
When the cover of the protected two-way testing
module is in the open position, lip 224 located on the
top of each contact, is exposed above the gasket 232 so
that an alligator-type or equivalent test connector can
be conveniently connected to either the service wire test
contact 214 or the exchange wire test contact 216 for
testing.
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As in the two-way testing module 200, the service
wire and exchange wire test contacts 214 and 216, the
earth junction contact 144 and the gas discharge tube 142
are maintained within the protected two-way testing
module 240 with a hard encapsulant such as a non-
conductive epoxy. The hard encapsulant only occupies a
portion of the interior of the protected two-way testing
module 240, as in the two-way testing module 200. The
remainder of the interior of the two-way testing module
240 is sealed by gasket 232. The gasket 232 protects the
junction between the service wire test contact 214, the
exchange wire test contact 216 and the bayonet contact
210. Therefore the connection between the service side
and the exchange side, formed when the cover is closed
and the bayonet contact is inserted into the slot 222
provided in the service wire test contact 214 and the
exchange wire test contact 216, is protected from the
environment by the gasket 232. Preferably, the
interstitial space between the encapsulant and the gasket
is filled with an insulating media which further protects
the junction from the environment.
In addition, a test probe may be inserted into tee-
in test port 44, when the cover is in the closed
position, to perform diagnostic tests on the connection
between the service side and the exchange side while
maintaining the conductive connection between the two
sides. The two-way testing module 200 and the protected
two-way testing module 240 may be used interchangeably
with the housing 12, and the five-prong access jack 120,
depending on the application desired by the user.
Referring to Figure 5, prior to use of the terminal
block of the present invention for exchange wire and
service wire connection, and preferably during
manufacture or assembly of the terminal block, a suitable
insulating medium is injected into chambers 150 and 160
and above the hard encapsulant within the bridge module
40 and the protector module 140 so as to fill all the
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voids and the wire openings in the terminal block. In
addition, the voids in the two-way testing module 200 or
the protected two-way testing module 240 may also be
filled in a similar manner. Any one of a large number of
well known commercially available greases, gels and other .
insulating mediums may be employed, depending on the
specific requirements of the application.
The viscosity and adhesive qualities of the medium
should be such that wires may be inserted to and removed
from openings 56, 166 and 44 without adhering excessively
to the medium. The medium should be sufficiently
flowable so as to flow around the exchange wire carrier
and the service wire carrier 50 as they move
therethrough. The medium may be injected into the
15 chamber 150 through terminal actuator 32 through a
central bore therein. This central bore in terminal
actuator32 is then secured with a plug 54 to ensure the
medium 28 remains within the chamber once the chamber is
filled. Similarly, perforated seal 58 also helps prevent
20 the medium from flowing out through the service wire
receiving openings 56. The medium is also injected into
test port 44 in order to fill the bridge module 40 and
the protector module 140 and into chamber 160 through
exchange wire receiving opening 166. The medium is also
injected through the gasket 232 to fill the two-way
testing module 200 and the protected two-way testing
module 240. Injection of the medium may be performed
after assembly of the terminal block. Also, the medium
may be pumped in after being precured outside of the
block in the case of a curable medium such as a gel, or
may be injected in an uncured state and subsequently
allowed to cure. -
In the field, the exchange wires desired to be
connected to the terminal block are inserted into
openings 166 with the exchange wire carrier 20 configured
in a first open position illustrated in Figure 5. In
this position, the wires may be readily inserted into the
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interior of exchange carrier 20 displacing only a very
moderate amount of insulating medium. As may be
- appreciated from Figure 5, in the open position, the
diameter of the wire blocks the opening 166 preventing
outflow of the insulating medium therethrough. Once the
exchange wires have been inserted into the exchange wire
openings 166, the installer simply pushes the exchange
wire carrier 20 into the closed position. This may also
be performed in conjunction with snapping the carrier
into place on the mounting rail 24 as shown in Figure 6.
This motion drives the exchange wire carrier 20 upward.
In this position, the wires have been forced into contact
with exchange wire insulation cutting contact blades 170.
Insulation cutting blades 170 slice through the
insulation on the wires providing good electrical contact
to the inner conductive core of each wire. Because of
the flowable nature of the medium, as the exchange wire
carrier moves from the open to closed position, the
insulating medium is simply displaced from the chamber
160 to and opening 166 during closing. Thus, despite the
forcing up of the exchange wire carrier 20 and the wires
connected thereto, the volume of insulating medium in the
chamber 160 remains substantially constant, avoiding the
outflow of medium and/or the creation of any voids which
could allow the entry of moisture or contaminants from
the environment.
The medium is also preserved within chamber 150 when
connecting and disconnecting service wires in the field.
The service wires desired to be connected to the terminal
block are inserted into openings 56 through perforated
seal 58 with the service wire carrier 50 configured in a
a first position illustrated in Figure 5. In this
position, the wires may be readily inserted into the
interior of carrier 50 displacing only a very moderate
amount of insulating medium. As may be appreciated from
Figure 5, in the first position, the flanged extension 60
with perforated seal 58 of carrier 50 blocks the portion
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of wire access slots 14 below the openings 56 preventing
outflow of the insulating medium therethrough. Once the
wires have been inserted into the openings 56 the user of
the terminal block rotates terminal actuator 32 which in
turn drives the service wire carrier 50 downward due to
the threaded engagement of actuator 32 and the carrier
member. The medium is prevented from exiting through the
center portion of the actuator by plug 54. Actuator 32
is rotated until the carrier 50 is driven down to the
second position illustrated in Figure 6. In this
position, the wires have been forced into contact with
insulation cutting blades 64, 66. Insulation cutting
blades 64, 66 slice through the insulation on the service
wire providing good electrical contact to the inner
conductive core of the wire.
During the downward motion of the service wire
carrier 50, from the first position shown in Figure 5 to
the second position shown in Figure 6, the insulating
medium inside chamber 150 will flow around the sides of
service wire carrier 50 so as to be displaced from the
bottom to the top portion of the chamber 150. In this
regard, vertical channels 54 (seen most clearly in Figure
3) may be provided on service wire carrier 50 to
facilitate the flow of the insulating medium around the
carrier member as it is driven from the first to second
position by rotation of actuator 32. Thus, despite the
forcing down of the service wire carrier 50 and the wires
connected thereto, the volume of insulating medium in the
chamber 150 remains substantially constant, avoiding the
outflow of medium and/or the creation of any voids which
could allow the entry of moisture or contaminants from
the environment.
Unlike conventional terminal blocks, once installed
the terminal block may be removed from the mounting rail ,
and the exchange side wires removed and replaced as
required while maintaining the insulating medium within
the terminal block.
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As best illustrated in Figure 2, in order to remove
the terminal block 10 from the mounting rail 24 a tool
. such as a screwdriver may be used to apply force, pushing
the rear clip 30 away from the mounting rail, such that
the rear clip 30 may be disengaged from the mounting rail
24 and the entire terminal block lifted off of the
mounting rail.
As best illustrated in Figure 5, once the terminal
block is removed from the mounting rail the exchange side
wires may be removed and/or replaced. In order to remove
exchange side wires, downward force is applied to the
exchange wire carrier 20 by inserting a flat-headed tool
such as a screwdriver, into the exchange wire carrier
actuator slot 164. The downward pressure forces the
exchange wire carrier 20 into the open position and frees
the exchange wires from the exchange wire insulation
cutting contact blades 170. Once freed, the exchange
wires may be removed from the terminal block. In
addition, new exchange wires may be inserted into the
exchange wire carrier for installation if required. As
a result, the terminal block may be repeatedly used in
the same or a different installation, providing maximum
flexibility.
The service side wires may be removed by reversing
the terminal actuator movement. Reversing the rotation
of the terminal actuator forces the service wire carrier
upward, disengaging the service wires from the first and
second insulation cutting contact blades 64, 66. Once
disengaged the wire may be pulled out of the terminal
block housing. In this manner service wires may be
terminated, removed and replaced in the same terminal
. block, as required.
Accordingly, it will be appreciated that the
_ terminal block of the present invention provides
significantly improved environmental protection and
allows the multiple connection and disconnection of
exchange wires and service wires to the terminal block
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without significant loss of insulating medium and
concomitant loss of environmental protection capability.
Furthermore, the present invention provides a terminal
block which is simple to use and which is simple
mechanically and not prone to failure even after repeated .
connections and disconnections. In addition, the
terminal block of the present invention provides a bridge
module or protector module for conveniently and safely
connecting the exchange and service sides, as well as a
five-prong access jack for use by additional modules as
desired.
Referring to Figures 3 and 4, an exploded side view
of the present invention is illustrated which illustrates
the ease of manufacture of the present invention. As
illustrated, each of the components of the terminal block
within housing 12 is moved into position and captured by
the housing insert 70 and the housing 12. Thus, it will
be appreciated that the present invention, in addition to
providing the features described above, may also be
manufactured in a cost effective manner, readily
compatible with existing manufacturing technologies.
While the foregoing description has been of a
presently preferred embodiment of the present invention,
it should be appreciated that the terminal block of the
present invention may be modified in a wide variety of
ways while still remaining within the spirit and scope of
the present invention. For example, the specific
configurations of the housing, housing insert, exchange
wire carrier, earth connection on the mounting rail, and
service wire carrier may all be varied due to specific
manufacturing considerations or other reasons without
departing from the spirit and scope of the present ,
invention. Furthermore, while the present invention has
been described as a terminal block adapted for use with
insulated exchange and service side wires, the present
invention may equally well be employed with bare exchange
or service wires. Additional variations and
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modifications of the preferred embodiment described above
may also be made as will be appreciated by those skilled
in the art and accordingly the above description of the
present invention is only illustrative in nature.
