Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
o~
Field of the Invention
This invention relates generally to high voltage power
distribution systems and more particularly to connector apparatus
for providing separable interconnection of electrical cablss of
these systems.
B_ck~ound of the Invention
Three situations are typically encountered in the con-
nection and disconnection of electrical connectors in power dis-
tribution systems. Ihe so-called ~'loadmake" situation involves
the joinder of male and female contact elements~ one energized
and the other engagec with a normal load. An arc of moderate
intensity is struck between the contact elements as they approach
one another and until joinder~ The so-called 7l1Oadbreak" situa
tion involves the separation of such mated male and female con-
tact elements, while thye supply power to a normal load. Moderate
intensity arcing again occurs between the contact elements from
the point of separation thereof until they are somewhat removed
from one another. The so-called "fault closure" situation invclves
the joinder of male and fe~ale contact elements, one energized and
the~oth~r engaged with a load having a fault, e.g., a shorti^cir-
cuit condition. Quite substantial arcing occurs between the con-
tact elements as they approach one another and until joinder,
giving rise to the possibility of explosion and accompanying
ha7ard to operating personnel.
Prior art efforst have reached a point wherein arcing
in the loadmake and loadbreak situations is accommodated to more
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than a satisfactory extent. Thus, connector assemblles in wide-
spread use employ materials which emit arc-quenching gas when sub-
jected to arcing, thereby adequately dissipating the moderate
intensity arcs occurring in these situations. Arcing in the load-
break situation may be accommodated even fllrther by connector
assembly structure providing for operator movement of the contact
elements, while mated, until the female contact element abuts
against a stop member and the male contact element separates there-
from at high velocity as disclosed in U. S. ~ueffer patent No.
3~259~726 and U~ S. Kotski patent No. 3,542,986.
~ evlces not employing the above-mentioned high veloclty
contact separating structure for loadbreak acco~modation, but
suited for use in all threee situations are shown in Ruete et al.
U.SS~ patent No. 3,539,972 and Brown U0 S. patent No. 3,65~,590
commonly-assigned herewith.
As respects the fault closure situation, certain prior
art efforts have locked to the use of the afo~ementioned arc-
quenching gas foD assistance in accelerating contact elements
into engagement. While such prior art gas-assigned contact ele-
ment engagement efforbs have proved advantageous, need exists forccontinued improvement in connectors relying on arc-quenching gas-
assistance in acco~modating the fault closure situation through
accelerated contact element engagement. Those prior art measures
involving arc-quench~ng gas-assisted contact element movement are
now discussed with particularlty~
1~4;~ Q
In U~ S. Whitney patent No. 1,955,215 and in the above-
mentioned Kotski patent No. 3,542,986, male and fe~ale contact
elements having an arc-quenching guide in the latter patent, are
joined in accelerated manner by the assistance of gas pressures
attending arcing. In these efforts, an open-ended female contact
element i5 supported by an open-ended piston movable in an axial
passage in the connector housing.~ Arc-quenching gas is said to
be conducted, ~ithout restriction, through the female contact
element to exert net pressure on the piston. The pisbon and
hence the female contact element are aecordingly displaced in the
- direction of the male contact element, facilitatlng ~oinder more
rapidly than would otherwise occur in the absence of such dis-
placement~ In freely conducting arc-quenching gas throughout the
continuous volume of a female contact a~d a pistonJ these prior
art efforts effect fault closure at the cost of less than desired
loadbreak perfor~ance, since~in loadbreak performance, it is
desirable that the arc-quenching gas be restricted to a confined
volume to facilitate containment of such conductive gas in the
contact region upon contact separation.
In still another arrangement in present use and de-
scribed ln Joy Manufacturing Company ~ulleting 215-4, January 1972,
a connector housing includes an axial passage and fixedly supports
therein a female contact element defining a chamber for receiving
arc-quenching gas. The housing defines a cavity and includes a
valve closing one end of the female contact element and there~y
separating the female contact element cbamber from the housing
~o~o~o
cavity. A piston disposed in the housing passage encircles the
fixed female contact element and is in slicling engagement there-
with.~ The piston supports an arc-quenching guide and a ring-
shaped contact element for joint movement therewith. The ring-
shaped contact element engages the male contact element on its
insertion in the housing at a time prior to ~oinder thereof with
the fixed female contact element. A~c-quenching gas generated by
the arc struck between such ring contact and the male contact ele-
ment during fault closure is conducted into the fixed female con-
tact element chamber and operates the valve, the gas thereuponentering the cavity and moving the piston toward the male contact
element. Prior to ultimate engagement of the male and female
contact elements, fault current flows through the ring-shaped con-
tact element and is transferred to the female contact element
through sliding frictional engagement thereof with the piston.
This arrangement is less than desirable in that circuit resistance
varies widely during fault closure due to its dependence on indeter-
minate sliding frictional engagement between th~ piston and the
female contact element surfaces. Furthermore, since the female
contact element is fixed in the housing, and since the ring~shaped
contact element does not frictionally engage the male contact ele-
ment, this Joy device does not involve the aforementioned Rueffer
patent loadbreak assise, and accordingly effects accelerated fault
closure at ~he cost of less than desired loadbreak performance.
Summarv of the Invention
An object of the present invention is to provide con-
nector apparatus for use in loadmake~ loadbreak and fault closure
~0430(~(J
situations and which is adaptive in its operation to individually
serve the needs of each situation.
Toward the attainment of this and other objects, the
invention provides connector apparatus incorporating a housing
having opposed ends and an axial passage therebetween, means
defining a cavity in said passage, a piston assembly dispvsed in
said passage and comprising an arc-quenching guide, a female con-
tact element having a chamber into which arc-quenchlng gas is
directed, a piston supporting the ~uide and the female contact
element for ~oint movement and gas-pressure responsive valve
means for separating the female contact element and the housing
cavity and operable to selectively move the piston assembly to
accelerate contact element joinder in fault closure situations,
and means providing continuous electrical connection to the
female contact element of substantially fixed resistivity.
- As contrasted with the various functional capabilities
provided separately or in limited groupings in the prior art con-
nector apparatus discussed above, the above-summarized and other
apparatus according with the invention provides these and other
capabilities compositively. Such apparatus provides for pre
selected positioning of its movable female contact element for
assisting loadmake, a degree of freedom of movement for said
female contact element for movement thereof while mated with a
male connector and gas confinement capacity in said female con-
tact element to enhance loadbreakJ and selective gas-assisted
movement of said femaleecontac~ element while providing invarlant
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electrical continuity thereto, thus facilitating fault
closure.
According to the invention t:here is provided a separ-
able female connector for use in connecting or disconnecting
an energized high voltage circuit by engagement or disengage--
ment with a complementary connector having a male contact
element, said connector comprising:
a housing, said housing having first and second ends
and an axially extending opening therebetween,
a female contact assembly in said housing opening, said
assembly including
(a) a tubular sleeve having piston means at one end
thereof for defining a first chamber within said tubular
sleeve,
(b) female contact means fixedly positioned with
respect to said tubular sleeve in said first chamber for en-
gaging said male contact element, said female contact means
being electricallv connected to said piston means,
(c) gui.de means at the other end of said tubular
sleeve for receiving and guiding said male contact element
for movement within said first chamber, and for evolving arc-
quenching gas in response to an arc being struck between said
male contact element and said female contact means during said
movement,
said tubular sleeve being mounted in said housing open-
ing for axial movement between a first position wherein said
piston means is substantially adjacent to said second end of
said housing and a second position wherein said piston means
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is located between its said flrst position and said first end
of said housing,
said housing opening definirlg a second chamber,.
said female contact assembly further including
(d) valve means responsive to arc-quenching gas of
predetermined pressure in said first chamber to provide a
passage from said first chamber to said second chamber for
applying said gas to said piston means thereby displacing said
tubular sleeve from said first position to said second posi-
tion and accelerating engagement of said female contact means
with said male contact element to extinguish said arc,
biasing means between said housing and said tubular
sleeve for normally main~aining said tubular sleeve in said
first position, for permitting joint movement of said male
contact element and said tubular sleeve between said first
position and said second position during withdrawal of said
male contact element from said connector, and for accelerat-
ing the return of said tubular sleeve to said first position
upon disengagement of said male contact element from said
female contact means,
terminal means in said second end of said housing
adapted for connection in a high voltage circuit, and
conductor means disposed interiorly of said second
chamber between said second end of said housing and said
piston means for electrically connecting said piston means
and said terminal ~eans.
According to a further embodiment of the invention there
i5 provided a separable female connector for use in connecting
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or disconnecting an energized high voltage circuit by engage~
ment or disengagement with a complementary connector having
a male contact element, said connector comprising:
a housing, said housing having first and second ends
and an axially extending opening therebetween,
a female contact assembly mounted for axial movement
in said houslng openlng, said assembly including
(a) a tubular sleeve having piston means at one end
thereof for defining a first chamber within said tubular
sleeve,
(b) female contact means fixedly positioned with
respect to said tubular sleeve in said first chamber for
engaging said male contact element, said female contact means
being electrically connected to said piston means,
(c) guide means at the other end of said tubular
sleeve for receiving and guiding said male contact element
for movement within said first chamber, and for evolving arc-
quenching gas in response to an arc being struck between said
male contact element and sald female contact means during
said movement,
said housing opening de~ining a second chamber,
said female contact assembly further including
: ~d) valve means responsive to arc-quenching gas
of predetermined pressure in said first chamber to provide
a passage from said first chamber to said second chamber
for applying said gas to said piston means thereby displacing
said female contact assembly and acaelerating engagement of
said female contact means with said male contact element to
~1 -6b-
1C)430~0
extinguish said arc,
terminal means in said second end of said housing
adapted for connection in a hlgh voltage circuit, and
conductor means disposed interiorly of said second
chamber between sai~ second end of said housing and said
piston means for electrically connecting said piston means
and said terminal means.
In a further aspect the present invention provides:
; 18. A female connector for use in connecting a male contact
10 element with an energized high voltage circuit, said connector
comprising:
z
a housing having a first end adapted to receive said male
contact element, a second end adapted to be substantially closed
c ~ ~ C V
, O and an axially extendiny opening therebetween,
an elongate female contact assembly in said housing open-
ing, said assembly including
(a) a tubular sleeve having piston means, said sleeve being
axially movable between a first position wherein said piston
means is maximally spaced from said first housing end and a
second position wherein said piston means is minlmally spaced
from said first housing end, said piston means providing said
assembly with a first chamber remote from said second housing
ca
20 ~ ~ end and a second chamber adjacent said second housing end,
r Z~ (b) female contact means in said first chamber for engaging
v ~ ~ said male contact element, said female contact means being
z ~ v o
carried by and movable with and in electrically conductive
relationship with said sleeve,
(c) means for evolving arc-quenching gas in said firs~
chamber in response to an arc being struck between said male
contact element and said female contact means as said male
contact element approaches said female contact means, and
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(d) means for maintaining said sleeve in said first
position until the gas pressure ~f such evolved arc-quenching
gas attains a predetermined value and for permitting said sleeve
to move toward said second position when said pressure exceeds
said predetermined value, under the influence of gas pressure
exerted on said piston means in said second chamber.
In one aspect the sleeve and the female contaGt means
may be separate parts.
19. The connector claimed in claim 18 wherein said sleeve and
said female contact means are separate parts.
20. The connector claimed in claim 18 wherein a valve is
situated between said first and second chambers, said valve
being normally closed but openable to permit flow of gas from
Cu~ said first chamber to said second chamber.
a) 'ù ~
z ~ ~ ~ 21. The connector claimed in claim 20 wherein said means for
o ~
u ~ maintaining said sleeve in said first position comprises said
valve.
22. The connector claimed in claim 21 wherein said piston
means has a closed wall at an end thereof adjacent said second
housing end and said valYe is in said wall.
23. The connector claimed in claim 21 wherein said valve
somprises a disc rupturable at said predetermined pressure.
o
24.- The connector claimed in claim 20 wherein said valve is
u ~ z~ reclosable.
~- ~ v Q ~
o~ 25. The connector claimed in claim 21 wherein said maintaining
means further comprises means resiliently biasing said sleeve
in said first position.
26. The connector claimed in claim 25 ~here~n said biasing
means is a spring~
A valve may be situated between said first and second
chambers, said valve being normally closed but openable to
; permit flow of gas from said first chamber to said second
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chamber. In such a c~se said means for maintaining said
sleeve in saia first position may comprise said valve. In one
aspect said position means may have a closed wall at an end
thereof adjacent to said second housing end and said valve may
be in said wall. Said valve may comprise a dlsc rupturable at
said predetermined pressure.
The foregoing and other objects and features of the
invention will be evident ~rom the following detailed dis-
cussion of preferred embodiments thereof and from the drawings
wherein like reference numerals iaentify like parts throughout.
~ESCRIPTION OF THE DRAWINGS
Fig. 1 is a side elevation in full cross-section of
connector apparatus in accordance with the invention, shown
with a male cantact element and high voltage cable separab~y
connected thereby.
Yig~ 2 is a view ta~en along line II-II of Fig. 1,
illustrating one type of valve employable in practicing the
invention.
Fig. 3 illustrates the state of the Fig. 1 apparatus
in completed loadmake activity.
Fig. 4 illustrates the state of the Fig. 1 apparatus
immediately prior to loadbreak activity.
Fig. 5 illustrates the state of ~he Fig. 1 apparatus
duriny the course of ault closure activity.
:'
DESCRIPTIO~ OF PREFERRED EMBODIMæNTS
~`Referring to Figs. 1 and 2 pin-shaped male contact
element 10 is connected through a suitable colmector housing
to a high voltage electrical conductor (not shown) and supports
- a follower 12 abricated of a material suitable for evolving or
generating an arc-quenching gas upon being subjected to axcing.
A female contact element 14 includes resilient fingers 14a for
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faciliting gripping joinder thereof with contact element 10,
attainaible following insertion of follower 12 into composite
housing 16. Housing 16 defines an axial openlng or passage be-
twsen its opposed ends and includes an outer member or casing 18
preferably formed of elastomeric insulative material, an inner
member or sleeve 20 and an insulative material, an inner
member o~ sleeve 20 and an insulative insert 22 interlatched with
sleeve 20 as shown. Sleeve 20 is comprised or rigid conductive
material, e~g~, aluminum, and defines a region of uniform electri-
cal potential interiorly of casing 18. Casing 18 may include a
sleeve 24 preferably of donductive elastomeric material molded
to the exterior of the casing as generally `indicated for estab-
lishing a shield at the same electrical potential as supporting
structure~S such as a wall of a transfor~Pr casing, for example.
Conductive base 26 is seated in one end of the housing a~ial
passage and comprises a condurtive insert equipped with a th~eaded
bore 26a or the like for receiving the threaded extension 28 of
an electrical cab~le~30 comprising, for example, a lead-in con-
nection to a winding of such transformer. 0~ engagement thereof,
base 26 and cable exeension 28 effectively close one end of the
. .
housing passage.
A piston o~ female contact assembly is disposed in the
housing passage for sliding displacement and co~prises an elec-
trirally conductive piston 32, female contact element 14, a
tubular insulative sleeve 34, guide 36 and valve 38. In the il-
lustrated construction of the piston assembly, piston 32 includes
a through bore interiorly threaded in part and female contact
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~300~
element 14 is threaded exteriorly for fixed securement in the
piston bore. Tubular sleeve 34 is secured, e.g~, by an adhesive,
to female contact element 14 and in turn encirclingly supports
guide 36 through ~he use of a like adhesive. By this arrangement
all elements of the piston or female contact assembly are jointly
movable.
Guide 36 is comprised of arc-quenching material, pre-
ferably, though not necessarily, the same as that of the follower
12, and functions to receive and guide follower 12 and contact
alement 10 and to provide mutual alignment of the Fig. l apparatus
and the housing (not shown) for male contact element 10.
Valve 38 is seated in the piston bore against centrally
apertured piston wall 32a and is held securely in place by ring
40 ag-1nst which bears one end of contact element 14. One form
-~ of valve suitable for use in practicing the inve~tion is shown
in Figso 1 and 2~ the detail thereof being best seen in Fig. 2
wherein rupturable resilient member or disc 38a and wire screen
38b provide a closed or substantially gas-impermeable structure
when the differential in gas pressure thereacross is less than a
predetermined gas pressure differential. In response to differen-
~ tial pressure equal to or exceeding such predetenmined differen-
-~ tial, the valve is ruptured as shown in Fig. 5~ As discussed
- below~ such predetermined gas pressure differential is that occur-
ringgupon fault closure activity. Screen 38b reinforces member
38a to avert rupture at gas pressure differentials lower than
said predetermined pressure differentialO
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Pin 42 isssupported by housing 16 axially spaced from
base 26 and projects into the housing passage for defining a
chamber or cavity 16a of no lesser axial extent than such spac-
ing.
In the position thereof illustrated in Fig. 1~ piston
32 abuts pin 42 under the influence of biasing or resilient means,
preferably comprising a compression spring 44. Sleeve 20 includes
an expanse of increased diameter defining a shoulder 20a for seat-
ing one end of the spring. The other end of the spring bears
agsint piston 32. Pin 42 thus functions as a stop or limiting
means, preventing displacement of the piston assembly into the
above-mentioned axial cavity. Under these conditions, tubular
sleeve 34 is disposed in a first position wherein piston 32 is
substantially ad~acent the end of the housing seating ~base 26.
The piston assembly defines an axial chamber inclusive
of the interior hollows of guide 26~ slee~e 34 and female contact
element 14, such chamber being isolated from the above-men~ioned
housing chamber or axial cavity when valve 38 is closed~
.,
;-~ Conductors or connectors 46 are disposed in such cavity
and the ends of the ca~le are secured respectively to base 26 and
~`; - plston 32. Conductors 46 provide electrical continuity of sub-
~- stantially fixed resistivity between piston 32 and base 26 and
- accordingly between fe~ale contact element 14 and cable 30.
Characteristics of the ~ig. 1 apparatus other than
:..
those elicited in the foregoing discussion will be evident from
the following description of the operation of such structure
'.'~
~ 3~
respectively in loadmake, loadbreak, and fault closure activity.
Loadmake:
With the component parts of the apparatus in position
illustrated in Fig. 1, follower 12 is inserted into guide 36.
Spring 44 normally maintains sleeve 34 ancl piston 32 in the above-
mentioned first position. With the pisto~l in such easily recog-
nized and certain position and upon abutment between follower 12
and resilient fingers 14a, alignment of the male contact element
housing with the female contact element housing as well as operator
stance may be checked for any necessary correction. Upon con-
tinued insertion of follower 12, resilient fingers 14a are spread
and frictionally engage the follower periphery. In the course of
such continued insertion, an arc is struck prior to engagement of
` fingers 14a with contact element 10. Under normal load conditions
in the circuit connected to cable 30, the energy of such arc is
moderate. Durin~ the course of arcing, guide 36 and follower 12
emit arc-quench ing gas. The arc may persist at intensity lessened
by the qoenching gas until fingers 14a engage contact element 10.
~ Throu~hout persistence of the arc, all arcing current flows through
;- 20 ~ definite electrlcal path of substantially fixed resistivity be~
tween cable 30 and its ~innshown counterpart cable~ such path com-
prising pin 10, contact element 14, piston 32~ cables 46 and base
~-~ 26~ Under such loadmake conditions valve 38 isolates cavity 16a
. . ~
from the piston assembly chamber and is effective to confine arc-
quenching gas to the region of the arc.
- ~43~01;~
Fig. 3 shows the connector apparatus on completion of
loadmake and in its princlpal usage, i.e., in energizing a
load. Loadbreak
In the event it is necessary or desirable to interrupt
electrical continuity between contact element 10 and cable 30
while the circuit ls energi~ed, element 10 is withdrawn from
housing 16 Since contact fingers 14a apply a frictional force
to element 10 exceeding the force applied by spring 44 to
piston 32, the piston assembly is withdrawn jointly with ele-
ment 10, i e., sleeve 34, element 14 and element 10 move
jointly, up to the point at which shoulder 20a and then com-
pressed spring 44 limit piston assembly movement in the direc-
tion of withdrawal as shown in Fig. 4. Sleeve 34 is thus in
a second position wherein the piston is located between its
first position and the end of the housing rfceiving element 10.
At this juncture, element 10 moves relative to the piston
assembly and ultimately separates from contact element fingers
14a at which time an arc is strucX therebetween. Such arc ls
quenched by gases generated by guide 36 and f~llower 12 and i9
ultimately extinguished as the contact elements urther separate
and the follow~r thereafter exits from guide 36. Arc extinction
is abetted since element 10 not only exits from contact element
14 at substantially the speed of movement imparted thereto by
the operator but furthermore since tubular sleeve 34, hence
contact element 14, is itself rapidly returned to its normal
first position upon disengagement from element 10 and follower
1~ under the influence of spring ~4, thereby facilitating
accelerated separation of these contact elements. Such rapid
3~
return preferably commences when the follower 12 is partially
withdrawn from female contact element 14. In order to faci-
li~ate the foregoing, the pin follower 12 may be slightly
tapered along its axial extent.
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It will be understood that initial joint movement of the con~act
elements and subsequent relative sliding movement therebetween may
occur during withdrawal of the male contact element before spring
44 is fully compressed.
While valve 38 is inoperable during the above-discussed
loadbreak situation, its presence nevertheless contributes sub
stantially to the loadbreak pe~formance Jof a connector assembly
having capacity for gas-accelerated contact engagement during
fault closure, as will be discussed after the following explana-
tion of fault closure activity.
Fault Closure
To the ex~ent that an operator is unaware of the exist-
ence of a fa~lt condition in a load~ he approaches this situation,
as in the loadmake situation above-discussed, by inserting fol
lower 12 in guide 36 and checking stance, allgnment and like con-
siderations. The follower is then inserted within contact element
fingers 14a and~ as element 10 approaches the fingers, an arc of
quite high intensity is struck~ producing a shock wa~e in the
~ piston assembly chamber and thereby creatlng said predetenmined
- :
pressure differential across valve 38~ Valve 38 is accordingly
ruptured. On this event arc-quenching gas passes from the piston
assembly chamber, through the ruptured valve and into cavity 16a
and exerts a net force on piston 32 displacing the same toward
element 10 as shown in Fig. 5. Accordingly, contac~ element
fingers 14a are accelerated into engagement with element lO,
extinguishing the arc~
-12-
31DO~)
In providing, in a composite structure9 performance
capabilities approached separately or in limited groupings in
presently-used connector apparatus, the apparatus of the invention
gains certain performance benefits. By w~y of example alluded to
above, valve 38, operable exclusively in fault closure activity,
abets loadbreak performance although then inoperable. Yundamental
to such fault closure activity is the requirement for a housing
cavity located on the side of a piston assembly copposite that side
thereof toward which the male contact element is advanced. Such
cavity constitutes gas-accessible volume additive to that of the
piston assembly chamber. In the course of loadbreak, however,
such additive gas~accessible volume is undesired since it~is
believed tha~ the same lessens the vacuum created within the
housing upon withdrawal of the male contact element. Th~ level
of such created vacuum controls the inrush of ~ir which counter-
:~,
acts arc-generatedd gas and prevents the same from flushing out
between the separated housings and forming an undesirable conduc-
tive path to ground. A desired higher vacuum level during load~
~-` break in a connector also adapted for fablt closure is attained
in substantial par~ by means such as valve 38.
A particolarly desired feature wllich may be introduced
in connectors according with the invention for purposes of mini-
=izing- arcing and decreasing the gas generated by arcing during
fault closure involves the spacing of contact element 14 from
guide 36 by an axial length no less than the order of magnitude
of one-half the dlstance between contact elements 10 and 14 at
_13-
-` ~0~3~
which an arc will be struck between the contact elements as con-
tact element 10 approaches contact element 14 under high voltage
fault conditions. Such spacing is indicated in Fig. 1 by the
reference designation S~
Various alternative valve constructions may be employed
in place of the preferred rupturable valve. Thus, for example,
the invention contemplates use of a duck-bill flap type of valve
which opens upon fault closure and reverts to its substantially
gas imperme~ble initial condition following fault closure activity~
i.e.~ a reclosable valve means.
Various additional changes to the particularly disclosed
and ill~strated connector apparatus and modifications in the pra~-
tice outlined above will now be evident to those skilled in the
art. The particularly discussed embodiment of connector apparatus
-~ according with the invention is accordingly to be considered il-
lustrative and not limiting. The true spirit and scope of the
invention is set forth in the following claims.
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