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Claims  |
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I claim:
1. A modular jack for receiving a modular plug of the type which includes a
dielectric housing having a free end for insertion into the modular jack,
a cord input end having a cavity for receiving a multi-conductor cord, a
resilient latching arm integrally connected by a flexible hinge to the
free end of the dielectric housing and extending obliquely rearwardly
therefrom, a terminal-receiving side having partitions which define
side-by-side slots in communication with the cavity, electrically
conductive contact terminals positioned within the slots and extending
into the cavity for making electrical engagement with associated
conductors of the cord, the contact terminals including
insulation-piercing tangs at the lower portion thereof and an outer edge
surface, the modular jack comprising:
(a) an insulating housing having a front end and a rear end;
(b) plug-receiving cavity means for receiving the modular plug extending
into said front end of said insulating housing and having a plurality of
internal walls including a rear wall;
(c) a wall member extending adjacent said rear wall of said plug-receiving
cavity means and having conductor-receiving means formed therein;
(d) a plurality of electrical conductors in side-by-side spaced-apart
relationship in said insulating housing, each of said conductors
comprising:
(i) a first portion positioned in said conductor receiving means of said
supporting wall; and
(ii) a spring contact portion extending from said front end toward said
rear end of said housing from said first portion into said plug-receiving
cavity means;
(e) commoning bar assembly means positioned adjacent said
conductor-receiving means of said wall member and including means for
maintaining continuous electrical contact between at least two conductors
which may be preselected from said plurality of electrical conductor; said
commoning bar assembly means maintaining continuous electrical contact
between said conductors when a plug is inserted into said plug receiving
cavity means;
(f) said spring contact portions of said conductors engaging the contact
terminals of the modular plugs after insertion of the plug into said
plug-receiving cavity means; and
(g) said plug-receiving cavity means further having recess means formed
therein for receiving and releasably retaining the latching arm of the
modular plug.
2. The modular jack of claim 1, wherein said means for maintaining
continuous electrical contact comprises at least two conductive fingers in
spring contact engagement with said at least two of said plurality of
electrical conductors.
3. The modular jack of claim 2, wherein said commoning bar assembly means
further comprises an elongated conductive strip extending transversely of
and adjacent to said first portions of said conductors, said at least two
conductive fingers extending integrally from said conductive strip.
4. The modular jack of claim 3, wherein said commoning bar assembly further
comprises means for mounting and retaining same in said insulating
housing.
5. The modular jack of claim 4, wherein said mounting and retaining means
comprises a plurality of retaining legs formed integrally with said
conductive strip and extending therefrom.
6. The modular jack of claim 1, wherein said spring contact portion extends
from said first portion into said plug-receiving cavity means from said
rear wall of said cavity means towards said front end of said insulating
housing.
7. The modular jack of claim 6, wherein said outer edge surface of said
contact terminal comprises a flat upper edge and wherein said spring
contact portions of said conductors include a substantially linear lower
surface for engaging said flat upper edge of said contact terminals.
8. A double-ended modular jack for coupling two modular plugs, each of the
modular plugs being of the type which includes a dielectric housing having
a free end for insertion into the modular jack, a cord input end having a
cavity for receiving a multi-conductor cord, a resilient latching arm
integrally connected by a flexible hinge to the free end of the dielectric
housing and extending obliquely rearwardly therefrom, a terminal-receiving
side having partitions which define side-by-side slots in communication
with the cavity, electrically conductive contact terminals positioned
within the slots and extending into the cavity for making electrical
engagement with associated conductors of the cord, the contact terminals
including insulation-piercing tangs at the lower portion thereof and a
substantially flat portion of an upper edge surface on at least one end of
which is formed a crown, the modular jack comprising:
(a) an insulating housing having first and second ends and a central
housing portion;
(b) first and second plug-receiving cavity means for receiving the modular
plugs extending into said first and second ends of said insulating
housing, each cavity means having a rear wall and a plurality of internal
side walls;
(c) conductor-receiving means extending through said central housing
portion from said first to said second plug-receiving cavity means;
(d) a plurality of electrical conductors in side-by-side spaced-apart
relationship, each of said conductors comprising:
(i) a central portion extending through said conductor-receiving means of
said housing; and
(ii) first and second spring contact portions extending from said central
portion into said first and second plug-receiving cavity means,
respectively, in the direction of the first and second ends of said
housing;
(e) commoning bar assembly means positioned adjacent said
conductor-receiving means and including means for maintaining continuous
electrical contact between at least two conductors which may be
preselected from said plurality of electrical conductors said commoning
bar assembly means maintaining continuous electrical contact between said
conductors when said plugs are inserted into said plug receiving cavity
means;
(f) said spring contact portions of said conductors including a mating
surface for engaging the contact terminals of the modular plugs after
insertion of the plugs into said plug-receiving cavity means; and
(g) said plug-receiving cavity means each further having recess means
formed therein for receiving and releasably retaining the latching arms of
the modular plugs.
9. The double-ended modular jack as set forth in claim 8, wherein said
first and second spring contact portions extend from said central portion
of said conductors into said first and second cavity means, respectively,
from said rear wall of said cavity means towards said first and second
ends of said insulating housing, respectively.
10. The double-ended modular jack of claim 8, wherein said conductors
comprise stamped-and-formed contacts, said mating surface of said spring
contact portion including a substantially flat lower surface for
contacting said flat upper edge surface of said contact terminal, whereby
the resultant contact area between said spring contact portion and said
contact terminal when in normal alignment comprises a quadrilateral.
11. The double-ended modular jack of claim 8, wherein said conductors
comprise round wires, said mating surface of said spring contact portion
including a rounded outer surface for contacting said flat upper edge
surface of said contact terminal, whereby the resultant contact area
between said spring contact portion and said contact terminal, when in
normal alignment, comprises a substantially thin elongated line.
12. The double-ended modular jack as set forth in claim 8, wherein said
means for maintaining continuous electrical contact comprises at least two
conductive fingers in spring contact engagement with said at least two of
said plurality of electrical conductors.
13. The double-ended modular jack as set forth in claim 12, wherein said
commoning bar assembly means further comprises an elongated conductive
strip extending transversely of and adjacent to said central portions of
said conductors, said at least two conductive fingers being formed
integrally with and extending from said conductive strip.
14. The double-ended modular jack as set forth in claim 13, wherein said
commoning bar assembly means further comprises means for mounting and
retaining same in said insulating housing. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to electrical connector receptacles
commonly known as modular jacks and, more particularly, is directed
towards a double-ended modular jack or coupler for use as an interconnect
device between two multi-conductor cables, each terminated by a modular
plug.
2. Description of Related Art
The desirability of providing a double-ended connector receptacle or
modular jack for end-to-end connection of modular plugs has been
recognized in the following U.S. Pat. Nos. 4,153,327; 4,268,109;
4,273,402; 4,367,908; and 4,379,609. The couplers taught in these patents
are characterized by the provision of a dielectric housing and a pair of
cavities opening into each end thereof. Each cavity is particularly
designed and sized to receive a mating modular plug of the type described,
for example, in U.S. Pat. No. 3,954,320 to Hardesty. Modular plugs and
jacks have gained wide acceptance in the communications industry, as well
as for use with general electrical and electronic equipment as
interconnect devices.
An improved double-ended modular jack is described in U.S. Pat. No.
4,460,234, assigned to the same assignee as the present invention. In the
'234 patent, a plurality of side-by-side conductors are employed which
have a greatly reduced length compared with the conductors of the
previously known couplers. This results in substantial cost savings both
with respect to the overall reduced length of the conductors themselves,
as well as with respect to the reduced amount of gold-plating thereof
which is provided to increase conductivity and reliability.
While an improvement over prior known designs, the coupler described in the
'234 patent nevertheless has a few drawbacks of its own. For one thing
(and this is a problem which is common to all previously known modular
jacks), the design of the spring contact portions of the conductors
provides only a small area of electrical contact with the contact
terminals of the male modular plug. Prior art modular jacks utilize a
linear (or slightly curved) diagonally extending spring contact portion
that makes contact with only the crown, or radiused end, of the contact
terminal of the modular plug. This results in essentially a single point
of electrical contact between the two components of approximately 0.0008
inch in diameter. Several problems arise from this configuration. For one
thing, when the conductors are carrying high frequency signals (e.g.,
20-40 MHz.), some information can be lost due to the small area of contact
(i.e., signal transfer area) between the plug and jack conductors.
Another problem with such spring contact configurations is that they do not
provide a uniform contact resistance as the plug is inserted and withdrawn
into and from the jack. This results from the fact that such spring
contact portions have a longitudinal force vector which increases and thus
creates more resistance to longitudinal movement of the plug as the plug
is inserted more deeply into the plug-receiving opening of the jack.
Conversely, the contact resistance lessens as the plug is withdrawn from
the cavity.
The single point of contact between the jack's spring contact portion and
the plug's contact terminal is also disadvantageous when the connectors
are utilized in an environment which is subject to vibration. In such a
case, electrical continuity may be intermittently and undesirably broken.
A further disadvantge of the prior art spring contacts is that they may be
easily overstressed if the wrong size plug is accidentally inserted into
the jack. Such overstress degrades contact reliability and essentially
ruins the jack for subsequent use.
In addition to the foregoing, the prior art couplers make no provision for
selectively but permanently commoning two or more conductors in order to
minimize the number of contact positions and wires required on one end of
the coupler to carry a particular signal (such as tip or ring) that may
come in on the other end of the coupler in more than one position. While
the '234 patent does teach a shorting bar arrangement (see FIGS. 7 and 8
and column 7 from line 34), the shorting bar only comes into play when the
modular plug is withdrawn from the coupler; it is ineffective when the
modular plugs are mated in the double-ended jack. I have discovered that
it would be very desirable to provide a double-ended modular jack with the
capability of selectively and permanently commoning two or more conductors
regardless of whether the modular plugs are in place in the jack.
The present invention is provided to overcome the above-noted deficiencies
and as an improvement over known modular jack couplers.
SUMMARY OF THE INVENTION
The foregoing and other objects and advantages are provided in accordance
with one aspect of the present invention through the provision of a
modular connector for coupling two modular plugs, which comprises a
dielectric housing having first and second ends, a central housing
portion, and first and second plug-receiving cavities extending inwardly
from the first and second ends, respectively. The first and second
cavities are adapted to receive first and second modular plugs therein,
respectively, and the housing includes a plurality of side-by-side
conductor-receiving guide means located in the central housing portion.
Each of the modular plugs terminates a multi-conductor cord by means of a
plurality of side-by-side, substantially planar, insulation-piercing
contact terminals positioned in the forward portion of the plug, the
contact terminals including a substantially flat outer edge surface.
The invention further includes a plurality of electrical conductors
positioned in a side-by-side spaced apart fashion in the housing. Each of
the conductors include a central portion and first and second spring
contact portions extending generally outwardly from respective ends of the
central portion into the first and second cavities, respectively, towards
the first and second ends of the housing. The conductor-receiving guide
means include means for supporting the central portions of the conductors.
Each of the spring contact portions preferably includes a substantially
linear beam mating portion.
The outer edge surface of the contact terminals of the modular plugs engage
the linear mating portions of the spring contact portions of the
conductors after insertion of the plugs into the cavities, and the free
ends of the first and second spring contact portions deflect outwardly
upon making and breaking of electrical contact with the contact terminals
of the plug.
In one embodiment, the conductors may comprise stamped and formed contacts,
the linear mating portion of the spring contact portion in this case
including a substantially flat outer surface for contacting the flat outer
edge surface of the contact terminal whereby the resultant contact area
between the spring contact portion and the contact terminals when in
normal alignment comprises a quadrilateral. In an alternate embodiment,
the conductors may comprise round wires whereby the resultant contact area
between the spring contact portion and the contact terminal when in normal
alignment comprises a substantially thin, elongated line.
In accordance with more detailed aspects of the present invention, the
spring contact portion further includes a leg portion and a free end
portion, the leg portion extending between the central portion and the
linear mating portion, the spring contact portion terminating in the free
end portion. The inner top wall of the each of plug-receiving cavities has
a plurality of side-by-side slot means formed in alignment with the
conductor-receiving guide means, the leg portions of the spring contact
portions extending partially within the cavities and partially within the
slot means. The free end portions of the spring contact portions are
freely movable in the slot means upon insertion and withdrawal of the
modular plugs into and out of the cavities. The linear beam mating
portions of the first and second spring contact portions in one embodiment
face opposite directions whereby the signals from the contact terminals of
the first and second modular plugs will be positionally matched.
In accordance with yet another aspect of the present invention, the angular
orientation of the linear mating portions of the spring contact portions
in the cavities is such that the modular plugs when inserted into the
cavities causes the linear mating portions to become substantially
parallel with the longitudinal axis of the cavities. Stated another way,
the linear mating portions of the spring contact portions are oriented at
a slight angle (e.g., 5.degree.) to the longitudinal axis of the cavities
prior to insertion of the modular plugs into the cavities. Each of the
spring contact portions may further include a diagonal portion extending
between the linear mating portion and the free end portion. Furthermore,
the contact terminals of the modular plugs include at least one crown
formed at the forwardmost end of the flat, elongated outer edge surface,
and the diagonal portion of the spring contact portion is angled in the
cavity to make initial contact with the forwardmost crown upon insertion
of the contact terminal into the cavity, the crown urging the spring
contact portion upwardly as the modular plug is inserted further into the
cavity.
In accordance with yet other aspects of the present invention, the
conductor-receiving guide means are formed at a height above the inner top
wall of the cavity. The central portions of the conductors lie in a plane
which is spaced above the plane of the inner top wall of the cavity, and
the conductor-receiving guide means comprise a plurality of side-by-side
channels extending longitudinally in the central housing portion. The
channels preferably include means for restraining the conductors against
longitudinal movement which, in turn, comprise a transverse set of
retaining partitions and apertures formed across the channels and adapted
to receive retaining tabs formed in the conductors at the approximate
midpoint thereof.
In accordance with yet another important aspect of the present invention,
the housing further comprises means for accommodating a commoning bar
assembly located underneath partition and groove means. The accommodating
means preferably comprises a channel extending tranversely to the
partition and groove means. A first commoning bar assembly is provided
underneath the central portion of the conductors in the channel. The first
commoning bar assembly preferably includes means for electrically coupling
two or more of the overlying conductors. In a preferred form, the coupling
means comprises an elongated center conductive strip, a plurality of
commoning fingers extending upwardly and outwardly from the strip, and
means for retaining the strip in the channel. The fingers are in constant
spring contact with those of the conductors that respectively overlie the
fingers. A second channel may be formed in each of the housing halves for
accommodating a second commoning bar assembly that is substantially
identical to the first commoning bar assembly.
In accordance with yet another aspect of the present invention, there is
provided a modular jack for receiving a modular plug of the type which
includes a dielectric housing having a free end for insertion into the
modular jack, a cord input end having a cavity for receiving a
multi-conductor cord, a resilient latching arm integrally connected by a
flexible hinge to the free end of the dielectric housing and extending
obliquely rearwardly therefrom, a terminal-receiving side having
partitions which define side-by-side slots in communication with the
cavity, electrically conductive contact terminals positioned within the
slots and extending into the cavity for making electrical engagement with
associated conductors of the cord and for making electrical contact
external to the plug, the contact terminals including insulation-piercing
tangs at the lower portion thereof and an outer edge surface. The modular
jack comprises an insulating housing having a front end and a rear end,
plug-receiving cavity means for receiving the modular plug extending into
the front end of the insulating housing and having a plurality of internal
walls including a rear wall, a supporting wall extending adjacent the rear
wall and having conductor-receiving means formed therein, a plurality of
electrical conductors in side-by-side spaced-apart relationship, each of
the conductors comprising a first portion positioned in the
conductor-receiving means of the supporting wall and a spring contact
portion extending from the first portion into the plug-receiving cavity
means, commoning bar assembly means positioned adjacent the
conductor-receiving means of the supporting wall and including means for
maintaining continuous electrical contact between at least two of the
plurality of electrical conductors, the spring contact portions of the
conductors engaging the contact terminals of the modular plug after
insertion of the plug into the cavity means, the plug-receiving cavity
means further having recess means formed therein for receiving and
releasably retaining the latching arm of the modular plug.
In accordance with more detailed aspects of the invention, the means for
maintaining continuous electrical contact preferably comprises at least
two fingers in spring contact engagement with the two electrical
conductors. The commoning bar assembly means further comprises an
elongated conductive strip extending transversely adjacent the first
portions of the conductors, the two fingers extending integrally from the
strip. Means for mounting and retaining the commoning bar assembly in the
insulating housing are also provided.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, aspects, features and advantages of the
present invention will be more fully appreciated as the same becomes
better understood from the following detailed description of the present
invention when considered in connection with the accompanying drawings, in
which:
FIG. 1 is an exploded, perspective view illustrating a preferred embodiment
of the modular connector coupler of the present invention;
FIG. 2 is a longitudinal sectional view of the preferred embodiment of the
present invention and which also illustrates the modular plugs with which
the present invention is utilized;
FIG. 2a illustrates an alternate embodiment of a contact terminal for a
modular plug together with a portion of the spring contact of the present
invention;
FIG. 3 is a top view illustrating one of the housing halves together with
conductors and commoning bar assemblies of the present invention which is
taken along line 3--3 of FIG. 1;
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 2;
FIG. 5 is an enlarged, perspective, broken view of the slot, partition and
groove assembly of the present invention;
FIG. 6 is an enlarged, cross-sectional, broken view taken along line 6--6
of FIG. 2;
FIG. 7 is a plan view of a first lead frame utilized with the present
invention;
FIG. 8 is a plan view of a second lead frame also used with the present
invention;
FIG. 9 is a diagrammatic sketch illustrating the intersection of a spring
contact portion of a conductor of a jack with the contact terminal of the
plug; and
FIG. 10 is a view similar to FIG. 9 but illustrating an alternate
construction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals represent
identical or corresponding parts throughout the several views, and more
particularly to FIGS. 1 and 2 thereof, the modular connector coupler with
selective commoning system is indicated generally by reference numeral 10.
Coupler 10 includes a pair of substantially identical dielectric housing
halves 12 and 12'. It is noted that the "lower" housing half 12 is rotated
180.degree. with respect to the "upper" housing half 12' prior to joining
the two halves. Throughout this specification, for ease in identification,
unprimed reference numerals will be utilized to indicate components of the
lower housing half 12, while primed reference numerals will indicate
corresponding components of the upper housing half 12'.
When the identical housing halves 12 and 12' are joined (see FIG. 2), the
overall coupler 10 forms at each end a pair of openings or cavities 14 and
16 sized to receive a pair of modular plugs 18 and 20, respectively. The
modular plugs 18 and 20 are of the type generally described, for example,
in the following U.S. Pat. Nos. 3,860,316; 3,954,320; 3,998,514; and
4,002,392, the disclosures of which are expressly incorporated herein by
reference.
Referring particularly to FIG. 2, each modular plug, such as modular plug
18, is generally characterized by a dielectric housing having a free end
22 for insertion into modular jack cavity 14. Plug 18 also includes a cord
input end 24 having a cavity formed therein for receiving a
multi-conductor cord 26. Modular plug 18 is further characterized by the
provision of a resilient latching arm 28 integrally connected to the free
end 22 of the housing by a flexible hinge 30. Latching arm 28 extends
obliquely rearwardly from the free end 22.
Modular plug 18 is further characterized by a terminal receiving side 32
having a plurality of parallel partitions formed therein that define
side-by-side slots. Each slot is particularly designed to receive and
retain a substantially flat, conductive, generally phosphor-bronze
gold-plated contact terminal 34. Each contact terminal 34 is, in turn,
characterized by a pair of insulation-piercing tangs 36 which extend from
the lower portion thereof for piercing the insulation and making contact
with an insulated wire of multi-conductor cord 26. Contact terminal 34 is
further characterized by an upper, generally flat, elongated outer edge
surface 38 which, in the preferred embodiment of the present invention,
serves as the external contact portion for modular plug 18. Upper edge
surface 38 is generally rectangular (approximately 0.077 inch long and
0.012 inch wide) and is defined on both sides by the generally parallel
side walls of the contact 34, and a pair of curved portions or crowns 40
and 40' formed one at each end of flat edge surface 38. The forwardmost
crown 40 is formed at a predetermined radius and is adapted to make
initial contact with the conductors of the jack, as is described in my
copending application Ser. No. 882,434, assigned to the same assignee as
the present invention, the specification of which is specifically
incorporated herein by reference. Modular plug 18 may also be provided
with a retaining bar 41, as is conventional, which serves as a strain
relief mechanism for multi-conductor cord 26.
Referring to FIG. 2a, there is shown an alternate configuration for a
contact terminal 34a for modular plug 18. Contact terminal 34a is similar
to terminal 34 and includes the customary insulation-piercing tangs 36a.
The upper contact surface 38a of contact terminal 34a is preferably flat
and extends, however, only on the top portion of a relatively short
protrusion 39 having a forwardmost crown or radiused end 40a substantially
identical to crown 40 of the first embodiment. Protrusion 39 drops off
rapidly to a flat, lower edge 41 that extends to the rear end of terminal
34a. The length of outer edge surface 38a may range, for example, between
0.005-0.015 inch, and is typically about 0.007 inch. The thickness of
terminal 34a remains about 0.012 inch. This configuration dispenses with
the rear crown and saves substantially on gold-plating costs.
Returning again to FIG. 1, each housing half, for example lower half 12,
includes outer side walls 42 and 44 between which extend a bottom wall 46
which forms the floor for the plug-receiving cavity 14. A pair of spaced
locking tabs 48 are provided for releasably retaining the latching arm 28
of mating modular plug 18. In addition to bottom wall 46, cavity 14 is
defined by a rear wall 50. Housing half 12 further includes a top wall 52
which is designed to mate adjacent to the opposed top wall 52` of upper
half 12'. Top wall 52 acts as a supporting wall for the electrical
conductors that are positioned in conductor guide means formed therein, as
will be described in greater detail hereinafter.
A pair of apertures 54 and 56 are formed in top wall 52 adjacent the rear
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