Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVED CONNECTOR ASSEMBLY FOR A GAS
This invention relates generally to connector
assemblies for gases, and has particular relevance to
gas connector assemblies utili2ed in hospitals and the
like for dispensing various medical gases such as
medical air, oxygen, nitrous oxide and nitrogen to
collecting bottles, anaesthesia machine tubing, inlets
and outlets, ventilators, incubators, flowmeters and
regulators, oxygen generators and Walker units,
wherever and whenever gas application is practiced.
While it will be evident from what follows that
the present invention is not limited to medical
applications, there are particular problems associated
with the current method of gas dispensing in hospitals
which this invention resolves. It is therefore
appropriate to discuss the drawbacks of the
conventional practice in this regard so that the
advantages of this invention will be more clearly
perceived.
20 BACKGROUND OF THIS INVENTION
The current construction of the medical gas
connector assemblies utilized in hospitals and the like
for dispensing medical gases such as nitrous oxide,
nitrogen, oxygen, etc., is such that there is a serious
risk of interchanging the gas-specific portions of each
connector assembly after disassembly for purposes of
repair or cleaning. The gas-specific portions of the
connector assemblies, for gases such as nitrogen,
nitrous oxide and air, define diameter-indexed, two
stage bores having a first diameter adjacent the
entrance Pnd and a smaller diameter further inward from
the entrance end. The connector elements at the ends
of hoses or gas using devices intended to receive the
different gases are also diameter-indexed, i.e. in two
steps, with a smaller diameter at the tip and a larger
diameter further inwardly from the tip. In each case,
the diameters of the hose connectors are complementary
to the appropriate diameters of the assemblies into
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which they are inserted. Once inserted, the
appropriate size of nut is threaded onto threads
externally of the assembly, to hold the connector in
place. Thus the nuts are also gas-specific. The
insertion of the connector depresses a plunger located
internally of the assembly, and this in turn opens a
check-valve to admit gas into the connector.
A standard code has been adopted throughout North
America in regard to hand-tightened assemblies for
dispensing medical gases, and is known generally as the
D.I.S.S. system IDiameter-Index Safety System). Simply
stated, the non-interchangeable indexing is achieved by
a series of increasing and decreasing diameters. Thus,
the gas for which the outermost diameter is largest
will also have the smallest innermost diameter. The
next gas would have a slightly smaller outer diameter
and a slightly larger inner diameter, and so forth.
This prevents full insertion of any but the connector
for the correct gas using device.
As previously stated, however, the part which
defines the two-stage bore of the D.I.S.S. system (as
constructed by a number of manufacturers) can itself be
removed by unscrewing from a rearward portion of the
complete assembly, normally called the rear coupler.
All of these portions, called front couplers, have
identical threaded bosses with the same thread size and
diameter ~9/16" - 18), and any one of them can be
threaded into all of the rear couplers. Thus it
occasionally happens that the serviceman, after
disassembly for cleaning or repair, inadvertently
interchanges the front couplers. In a medical
situation, of course, this is highly dangerous, and
could result in the administration of the wrong gas to
a patient.
Described and claimed in U.S. Patent Application
Serial No. 479532 filed on ~arch 28, 1983
is a valve assembly for dispensing a gas into a
suitable connector, the valve assembly consisting
essentially of an outer body and an inner body. The
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outer body has an internal passageway for the gas wnich
opens through a front end of the outer body, and the
inner body is threaded into the passageway from the
front. The inner body has an internal opening which,
with the passageway, defines a continuous passage. An
S axially movable plunger is located in the opening of
the inner body, and located in the passage is a valve
means which is normally closed but can be opened by
rearward movement of the plunger. The plunger and the
inner body have complementary, close-fitting, non-round
portions, such as a hexagonal interfit, by which
rotation of the plunger requires rotation of the inner
body. The plunger has a means by which a suitable tool
can rotate the plunger and thus also the inner body.
While the assembly described in the above-
mentioned patent application functions quite well, and
certainly solves a number of problems with the prior
art, there is room for still further improvement in
terms of safety, simplicity, lower cost, and
facilitating a higher rate of gas flow.
In terms of safety, it is seen as advantageous to
preclude loss of specificity through routine
maintenance of the valve or valves installed into a
D.I.S.S. coupler. In the structure to be described
herein, the coupler is to be left affixed to its
primary attachment, and the internal indexing diametersare a non-removable part of the coupler. This ensures
that the internal indexing diameters are not removed
during servicing.
Accordingly, it is an aspect of this invention to
provide an improved valve assembly of simplified
construction, lower cost and improved gas flow.
With particular reference to safety, it is an
aspect of the present invention to provide a
non-removable D.I.S.S. configuration in the outer body,
so that during maintenance and repair of the inner body
and plunger there is no risk that a non-conforming
gas-using device could be connected to a partially
disassembled outlet body.
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It has now been found that the previous assembly
described in the aforementioned patent application can
be simplified by the removal of a spring used to bias
the plunger into the forward position, in which
position the passage through the inner body is closed
S and the gas is prevented from escaping. This
elimination is not simply a matter of removing an
element previously part of the total combination,
because a realization that this removal is possible
leads to a much simplified plunger and inner body
construction, and in particular allows the inner body
to be much smaller than previously thought to be
possible. Furthermore, it is possible to carry out
this simplification while maintaining or even
considerably improving the gas flow rate through the
plunger.
GENERA~ DESCRIPTION OF THI~ INVENTION
Accordingly, this invention provides a valve
assembly for dispensing a gas into a connector of a gas
using device, which includes an outer body having a
forward end and a rearward end and having an internal
passageway for gas, the passageway containing a valve
s~at and a valve member which is lifted from the valve
seat by rearward pressure. An inner body is threaded
into the passageway of the outer body, the inner body
having an internal passage and a plunger within the
passage, the plunger including a forward hollow sleeve
portion and two arm portions extending rearwardly from
the sleeve portion at diametrally opposite locations,
the arm portions being linked at their rearward ends by
a bridge portion from which rearwardly extends an
activating member adapted to hold the valve member away
from the valve seat when the plunger is moved to the
rear. A sealing member on the plunger forwardly of the
activating member is provided for closing the intexnal
passage when the plunger is in a forward position. The
inner body defines two opposed, internal, longitudinal
grooves for receiving the arm portions, thus
interlocking the plunger and the inner body so that
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rotation of the plunger requires rotation of the inrer
body. The bridge portion is engageable by a forked
tool for rotating the same.
GENERAL DESCRIPTION OF THE DRAWINGS
Two embodiments of this invention are illustrated
in the accompanying drawings, in which like numerals
denote like parts throughout the several views, and in
which:
Figure 1 is an exploded perspective view of the
inner body and plunger of one embodiment of this
invention;
Figure 2 is an end view of the inner body shown in
Figure l;
Figure 3 is an axial sectional view through a
valve assembly including an outer body and the
components of Figure 1 in assembled condition;
Figure 4 is a sectional view of the inner body and
plunger shown in Figure 1, the sectional plane being at
right angles to the plane used in Figure 3;
Figure 5 is a sectional view through a valve
assembly in accordance with a second embodiment of this
invention; and
Figures 6 and 7 are axial sectional views of two
tools for use with the invention.
DETAILED DESCRIPTION OF THE DRAWINGS
Attention is first directed to Figure 3, which
shows an outer body 10 adapted for use with a nitrous
oxide outlet and having a forward end 12 and a rearward
end 14. The outer body 10 has an internal passageway
16 for gas, which undergoes a number of different
changes in diameter. At the forward end 12, the
passageway 16 has a portion 18 of enlarged diameter
which is limited at the rear by a shoulder 20.
Rearwardly of the shoulder 20 is a bore 22 which is
threaded as shown at 24, and which terminates
rearwardly at a shoulder 26. Diameters 18 and 22 are
D.I.S.S. gas specific designates. Rearwardly of the
shoulder 26 is a portion 28 of smaller diameter, this
in turn being limited rearwardly by a restricted
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portion 32 having frusto-conical flanks. Exteriorly,
the outer body has a smooth cylindrical portion 34 ~t
the forward end, a threaded portion 36 rearwardly of
the portion 34, a shoulder 38 rearwardly of the
threaded portion 36, a hexagonal portion 40 rearwardly
of the shoulder 38, a cylindrical portion 42 rearwardly
of the hexagonal portion 40, an inward step 44
rearwardly of the cylindrical portion 42, and a
tapering pipe thread male connec~or 46 rearwardly of
the step 44.
Threaded into the bore 22 of the outer body 10,
engaging with the threads 24, is an annular valve
retention member 50 having a central passageway 52
defined by a frusto-conical portion 54 and a
cylindrical throat portion 56. Rearwardly, the member
50 defines a recess 58 for receiving a valve seat
member 60, the member 60 having a frusto-conical
rearwardly flaring surface 62 against which a valve
member, here shown in the form of a ball 64 can seat.
In addition, it will be seen in Figure 3 that the
member 60 defining the valve seat is adapted to be
compressed between the member 50 and the shoulder 26,
thereby providing a seal to prevent gas escaping along
the threaded connection between the member 50 and the
threads 24 of the bore 22.
At its forward end, the member 50 has a slot 66,
for receiving the end of a screwdriver by which the
member 50 can be inserted and removed. The sectional
plane in Figure 3 passes through the slot 66.
Also threaded into the bore 22 is an inner body 68
seen in section in Figures 3 and 4, in perspective in
Figure 1, and in end view in Figure 2. The inner body
68 has an internal passage 70 defined by a forward
frusto-conical portion 72, a central cylindrical
portion 74 and a rearward frusto-conical portion 76.
Exteriorly, the inner body 68 defines threads 78 for
engagement with the threads 24, and an annular recess
80 in which an O-ring seal 82 can be received.
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As best seen in Figure 2, the internal cylindrical
portion 74 of the passage 70 is interrupted by two,
opposed, C-shaped ridges 84, which can also be seen in
the sectional view of Figure 4. However, because the
ridges are separated by longitudinal gaps or grooves
86, the sectional view of Figure 3 (which is aligned
with the gaps 86) does not show the ridges.
The purpose of the ridges 84 and the grooves 86
will become apparent from what follows.
The inner body 68 is adapted to receive a plunger
88 which consists of two parts which are made
separately and then are locked together. In Figure 1,
a forward part 90 is shown to the right of the inner
body 68, and a rear part 92 to the left. The front
part 90 has a forward hollow sleeve portion 94
integrally formed with two arm portions 96 extending
rearwardly (leftwardly in the diagrams) from the sleeve
portion 94 at diametrally opposite locations with
respect to the sleeve portion 94. The arm portions are
linked at their rearward (leftward) ends by a bridge
portion 98, from which rearwardly extends an integral
projecting post 100. The bridge portion 98 has a flat
rearward face 102 perpendicular to the axis of the
cylindrical sleeve portion 94.
The rear part 92 of the plunger 88 includes a boss
104 having a frusto-conical rear surface 106, an
annular groove 108 for receiving an O-ring seal 110, a
flat rear face 111, and a rearwardly projecting
elongated activating member 113, having a tapering nose
115.
As can be seen particularly in Figure 4, the
maximum diameter of the boss 104 is greater than the
inside diameter of the C-shaped ridges 84, thus
preventing the rear part 92 of the plunger from passing
through the passage 70 in the inner body 68. Likewise
visible in Figure 4 is the fact that the maximum
diameter of the sleeve portion 94 of the front part 90
of the plunger is greater than the inside diameter of
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the ridges 84, thus preventing the front par~ 90 from
passing leftwardly through the passage 70.
It will now be evident why the plunger must be
manufactured in two parts. As seen in Figure 4, the
front part 90 and the rear part 92 are assembled to
each other with the post 100 being received in a bore
120 axially of the boss 104. The fit is very tight,
and a suitable locking compound is applied to ensure
that, once assembled, the front part 90 of the rear
part 92 cannot come apart.
In order to insert the front part 90 through the
passage 70, the arm portions 96 must he aligned with
the grooves 86. This alignment is maintained after
assembly of the plunger, and is such that both the
inner body ~8 and the plunger 88 must rotate together.
Thus, in order to rotate the inner body 68 with respect
to the outer body 10, it is necessary simply to grip
the plunger 88 and rotate it. Two instruments for
accomplishing this are shown in Figures 6 and 7.
Referring to Figure 6, which is an instrument suitable
for use with connections for N2, N2O, medical air and
vacuum, a sleeve 116 has an internal thread 117 for
engagement with the threaded portion 36 (Figure 3), and
threadably engages a boss 118 having an internal bore
119. Between the boss 118 and the sleeve 116 are
captured a resilient washer 120 and a disc 1~1.
Through the bore 119 passes a shaft 122 which has a
reduced portion 123 where an O-ring 124 is located. An
enlarged portion 125 prevents the shaft 122 from moving
further to the right than the position shown in Figure
6. Leftwardly from the enlarged portion 125 extends a
reduced neck 126 having a forked end 127 which is
adapted to engage the bridge portion 98 extending
between the two arm poxtions 96 of the front part 90
(see Figure 3). Thus engaged, the plunger can be
rotated by rotating the shaft 122. Such rotation is
facilitated by the presence of a knob 128 which is
securely mounted on a reduced portion 129 coaxial with
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g
the shaft 122. A further extension 130 projects
rightwardly from the knob 128.
Figure 7 shows a similar tool, which differs
primarily in that the sleeve 116 and boss 118 of the
Figure 6 tool are replaced by an integral nut 131
having an internal thread adapted to engage the outer
threads of an oxygen connector. Apart from this
difference, the tool of Figure 7 lacks the resilient
washer 120 and the disc 121. However, the function of
the two tools is the same.
A second embodiment of this invention is
illustrated in Figure 5, which is similar in many
respects to the embodiment shown in Figure 3. The
similar portions are not numbered or described in what
follows, in order to avoid needless duplication.
The embodiment of Figure 5 is particularly
suitable as an oxygen valve, and includes an outer body
lOa differing from the outer body 10 primarily in the
length of the threads 36a. The outer body lOa has a
passageway 16a which has an enlarged portion 18a at the
rightward (forward) end, a frusto-conical shoulder 19,
- and a cylindrical bore 22a of larger diameter than the
cylindrical bore 22 in Figure 3.
In the case of the Figure 5 embodiment, the inner
body 68a has a forwardly extending cylindrical portion
68b, which widens at the location 69 to define a
forward portion 69a which is too large in diameter to
enter the bore 22a. The portion 69a has a
frusto-conical lead-in 69b.
The inner body 68a has an enlarged bore 132
terminating at a rearward shoulder 134, rearwardly
joining a bore 136 of smaller diameter in which two
ridges (not visible in the section utilized for Figure
5) are located. These ridges again define diametrally
opposite grooves in which arm portions 96a of a front
part 90a of the internal plunger register. In this
embodiment, an annular rib 139 prevents further
leftward movement of the plunger, beyond the position
shown in Figure 5.
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The rear part 92 in Figure 5 is the same as the
part 92 in Figure 3.
It will be noted in Figure 5 that the inner body
68a has threads 78a for engaging ~he internal threads
24a of the outer body lOa. It will also be noted that
S the forward portions of the inner body ~8a are of too
great a diameter to pass into the region having the
internal threads 24a.
In the embodiments of both Figure 3 and Figure 5,
it will be noted that, with the plunger pulled fully
forwardly (the furthest right position in the
drawings), the elongated activating member 113 is in a
position to dislodge the valve member 64, and prevent
it from seating against the valve seat member 6~. It
will thus be appreciated that the ball 64 normally
never seats against the member 60, but simply lies
against the bottom of the chamber which contains it.
When the plunger is in its furthest rightward position,
thus closing the passageway against all movement of
gas, there is no gas pressure attempting to move the
ball 64. When the plunger moves leftwardly to allow
gas to escape through the inner body, there will be a
rush of gas rightwardly past the ball 64 which will
carry it in the direction of the valve seat member 60.
However, the position of the-activating member 113 will
prevent such seating from taking place, and therefore
no interference with gas flow will occur.
Thus, one can look at the annular O-ring 110 as a
primary seal, and the ball 64 as a secondary seal,
which comes into effect only upon removal of the inner
body from the outer body. This permits servicing of
the inner body and the plunger, without any leakage of
gas through the outer body.
It will further be appreciated that, particularly
in the embodiment of Figures 3 and 4, a substantial
simplification has been effected. No allowance needs
to be made for a spring member to urge the plunger into
the forward position, since the pressure of gas will
normally accomplish this. Furthermore, the opening
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11
through the front part 90 of the plunger is of
substantial dimension, thus interfering to the least
extent with gas f low . Finally, the construction
described above is one which does not require the
complex machining necessary to provide a hexagonal fit
between the plunger and the inner body. This
simplification reduces the cost of machining.
While two embodiments of this invention have been
illustrated in the accompanying drawings and described
hereinabove, it will be evident to those skilled in the
art that changes and modifications may be made therein
without departing from the essence of this invention,
as set forth in the appended claims.
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