Balanced pressure coupling

A coupler adaptor is provided for use in operative association with a container and a valve. The container houses relatively high pressurized carbon dioxide gas for use in carbonating a beverage. The valve is actuated in order to release the gas to an interface passage formed in the coupler adaptor. The coupler adaptor also has a pair of grooves formed on opposite sides of the interface passage for receiving O-rings. The coupler adaptor is also in operative association with a pressure regulator. The pressurized gas enters the pressure regulator from the coupler adaptor interface passage. In one embodiment, the coupler adaptor remains operatively joined to the pressure regulator without retaining structure due to the balanced gas pressure which results because of the O-rings positioned adjacent the coupler adaptor interface passage.

FIELD OF THE INVENTION 
The present invention relates to devices which are coupled to containers 
having pressurized fluids housed therein and, in particular, to a coupling 
apparatus which does not require retaining means for holding the coupling 
apparatus to a pressurized fluid-containing cylinder when the pressurized 
fluid is released therefrom to the coupling apparatus. 
BACKGROUND ART 
Various coupling devices are known for connection to a container housing 
fluid under pressure and in which the container or the coupling device 
includes a valve for releasing the fluid from the container into the 
coupling device. Each of these known coupling devices requires some 
retaining structure to maintain the coupling device and the container in 
secure operative association with each other when the pressurized fluid 
escapes the container and flows into the coupling device. As can be 
readily appreciated, the force of a highly pressurized gas exiting the 
container into a coupling device joined to the container can easily 
separate the container and coupling device. Typically, such retaining 
structure used in prior art coupling devices includes threads for 
interconnecting with threads formed in the container. Alternatively, the 
retaining structure includes a clamp or strap for maintaining a secure 
connection between a coupling device and the container or a valve. 
It has been found desirable to eliminate the use of such retaining 
structures in order to simplify the connection between a container or 
valve and the coupling device and to minimize the amount of space taken by 
the container, valve, and coupling device. As a result of simplifying 
these connections, the assembly and disassembly of the container is 
facilitated and enhanced. More specifically, it has been found 
advantageous to invert a pressurized fluid containing cylinder and provide 
a coupler adaptor for passing pressurized fluid into a pressure regulator 
without the use of retaining structure for holding the pressure regulator 
and cylinder together. In this regard the present invention includes a 
coupler adaptor which remains in operative association with the cylinder 
and pressure regulator when relatively high pressurized fluid is released 
from the container through a valve to the coupler adaptor and to the 
pressure regulator. The coupler adaptor remains joined to the container 
and pressure regulator because of a pressure balancing arrangement. 
PRIOR ART STATEMENT 
The following known prior art patent references are submitted under the 
provisions of 37 C.F.R. 1.97(b). 
U.S. Pat. No. 3,319,829 to Sentry discloses a pressure regulator which is 
connected to a housing by means of threads. The housing includes an 
opening for receiving a cylinder which houses gas under relatively high 
pressure. The gas is released into the pressure regulator in a direction 
parallel to its escape from the cylinder. An O-ring seal is provided 
adjacent the connection of the pressure regulator to the housing in order 
to prevent leakage of the gas. 
U.S. Pat. No. 2,524,052 to Grant, Jr. describes a valve assembly which is 
held by threads to a container. A valve operating member is joined to and 
movable relative to the valve assembly by means of a threaded coupling 
nut. An O-ring seal prevents leakage of gas between the coupling nut and 
the valve operating member. 
U.S. Pat. No. 1,910,283 provides a valve arrangement including a casing 
threadedly connected to a cylinder housing pressurized fluid. A thrust 
screw is used to permit the opening of a check valve and the escape of 
pressurized fluid. 
SUMMARY OF THE INVENTION 
A coupling assembly having a coupler adaptor is provided for connection to 
a container assembly. The container assembly houses pressurized fluid. A 
check valve is provided to retain the pressurized fluid. 
In one embodiment of the invention, the coupler adaptor includes a 
generally cylindrical body having the check valve extending therethrough. 
The cylindrical body is integrally joined to a housing which is threadably 
connected to the container assembly for housing the pressurized fluid. The 
cylindrical body includes two grooves. An O-ring is seated in each groove 
and an interface passage is formed between the two O-rings. The 
pressurized fluid moves past the check valve and through the interface 
passage to a pressure regulator. 
In another embodiment of the present invention, the container assembly 
includes a valve body having a recess into which the coupler adaptor is 
slidably fitted. The valve body houses the check valve. The coupler 
adaptor is threadably attached to a pressure regulator or other coupling 
device for receiving the pressurized fluid from the container. The 
pressurized fluid is released from the container assembly when the check 
valve is engaged. The pressurized fluid escapes from the container 
assembly into the pressure regulator through the interface passage formed 
in the coupler adaptor. A pair of O-rings is also included, as in the 
first embodiment, adjacent the interface passage. In both embodiments, the 
O-rings on both sides of the interface passage prevent leakage of the 
pressurized fluid when it is released from the container assembly and, 
most significantly, provide a substantial pressure balance so that the 
coupling device and container assembly remain in operative association 
during the release of the pressurized fluid. 
The present invention is particularly useful in a pressurization system, 
such as a carbonation system, wherein a container houses carbon dioxide 
under high pressure. The carbon dioxide gas in the container is permitted 
to controllably escape through the check valve and the coupler adaptor 
into a pressure regulator. The pressure regulator regulates the pressure 
of the gas which leaves an outlet port formed in the pressure regulator. 
Typically, the pressure regulated gas is used to pressurize a liquid, such 
as a soft drink. 
In view of the foregoing description, it is readily discerned that an 
efficient, yet simple, coupler adaptor is provided which is quickly 
plugged into or slidably fitted to a pressure regulator in one embodiment 
or a valve body in another embodiment for connection to a container. As a 
result, connection and removal of the container and coupler adaptor from 
the pressure regulator or the connection and removal of the container from 
the coupler adaptor and pressure regulator is quickly and easily 
accomplished even when the container contents are highly pressurized. 
Importantly, the coupler adaptor remains coupled to or in operative 
association with the pressure regulator or valve body without retaining 
structure for securing them together, even though escaping gas from the 
container provides a considerable force at the interface of the coupler 
adaptor and the pressure regulator or valve body. Coupler parts are 
thereby minimized and the space required for the container, coupler 
adaptor, and pressure regulator is reduced. 
Additional advantages of the present invention will become readily apparent 
from the following description when taken in conjunction with the 
accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In accordance with the present invention, a container assembly 10 including 
a cylinder 12 is depicted in FIG. 1 having a coupling assembly 14 attached 
to the cylinder 12 at its neck 16. The cylinder 12 is typically used to 
contain carbon dioxide under high pressure such that a portion of the 
contents of the cylinder 12 is liquid carbon dioxide while the remaining 
portions of the contents of the cylinder 12 are gaseous carbon dioxide. 
The gaseous carbon dioxide is, preferably, used to carbonate beverages, 
such as soft drinks. Accordingly, the present invention is primarily 
adapted for connection to another container which houses the beverage to 
be carbonated. When desired, the gaseous carbon dioxide is permitted to 
escape the cylinder 12 and coupling assembly 14 through the outlet tube 18 
into the container which houses the beverage to be pressurized or 
carbonated. 
The coupling assembly 14 includes a coupler adaptor. In a first embodiment, 
the coupler adaptor is threadedly connected to the cylinder 12. In the 
second embodiment, the coupler adaptor is threadedly connected to a 
coupling body such as a pressure regulator. The coupling body or pressure 
regulator is also an element or part of the coupling assembly 14. The 
present invention is particularly characterized in that, in the first 
embodiment, the coupler adaptor remains in operative association with the 
pressure regulator when pressurized gas is permitted to escape from the 
cylinder 12. Similarly, in the second embodiment, the coupler adaptor 
remains in operative association with the container assembly 10 and 
cylinder 12 when pressurized gas is permitted to escape from the cylinder 
12. This operative association in both embodiments does not necessitate 
the use of retaining structure, such as clamps, yokes, threaded 
attachments, and the like, unlike previously devised coupling structures 
wherein such retaining mechanisms were required. 
The present invention is also characterized, in its preferred 
configuration, by the inverted or upside down positioning of the cylinder 
12, as illustrated in FIGS. 1, 3, 4, 5 and 6. However, it is understood, 
as illustrated in FIGS. 2 and 7, that the present invention also properly 
functions when the cylinder 12 is positioned right side up. That is to 
say, the container assembly 10 and the coupling assembly 14 remain 
operatively connected without the use of retaining structure when the 
cylinder 12 is positioned upright and gas escapes from the cylinder 12 
into the coupling assembly 14. 
In this regard, the notable functional difference between the use of an 
inverted cylinder and an upright cylinder is that, in the inverted 
cylinder embodiment, the weight of the cylinder and the carbon dioxide 
contained therein act to overcome the force of the pressurized gas in the 
cylinder acting on a check valve stem for releasing the pressurized gas 
from the cylinder. This force tends to separate the container assembly and 
coupler assembly. With respect to the inverted cylinder embodiment, the 
coupler assembly is normally fastened to and supported by a horizontal 
support surface while the inverted cylinder is vertically positioned above 
the coupler assembly while joined thereto. Consequently, the force 
resulting from the pressurized gas against the check valve stem, tending 
to separate the coupler assembly from the container assembly, is fully or 
at least partially overcome by the downward acting force of the weighted 
cylinder. 
With respect to the upright cylinder embodiment in which the coupler 
assembly is again fastened to a horizontally extending supporting surface, 
the force resulting from the pressurized gas against the check valve stem 
tends to separate the cylinder from the coupler assembly. However, since 
the magnitude of the force against the check valve stem depends upon the 
magnitude of the pressure of the gas contained in the cylinder, this force 
is normally overcome by friction forces which resist the normal fluid 
force present in the cylinder. Additionally, the force against the check 
valve stem in an upright cylinder embodiment is minimized considerably 
through the use of a relatively small lateral or cross-sectional area. 
Also, this force can be negated by using a valve stem which is secured 
against movement in a direction towards the coupler assembly so that the 
force of the pressurized gas does not act to move the check valve. 
Although not shown in FIGS. 1 and 2, it is understood that standard support 
mechanisms are usually provided to rigidly maintain the combination 
container assembly 10 and coupler assembly 14 in either the upright or 
inverted configuration. Conventional supporting assemblies can be 
connected to either the container assembly 10 or the coupler assembly 14 
in order to prevent the overturning or tipping of the container assembly 
10 and coupler assembly 14 from their substantially vertical positions. 
Nevertheless, it is once again emphasized that such support structure is 
not used to interconnect the coupler adaptor and pressure regulator with 
respect to the aforementioned first embodiment or, alternatively, the 
coupler adaptor and container assembly with respect to the aforementioned 
second embodiment. It is also desirable, in selecting workable support 
structure, that ready access to the cylinder 12 be provided so that it can 
be easily replaced whenever the carbon dioxide contained therein has been 
expended. 
The detailed features of the present invention are shown in the two 
different structural arrangements identified here as the first and second 
embodiments. Although FIG. 6 depicts details of the invention with an 
inverted cylinder 12, while FIG. 7 illustrates details of the invention 
with an upright cylinder 12, it is readily appreciated that both 
embodiments of FIGS. 6 and 7 can be used with either an inverted or 
upright cylinder 12. 
With reference now to the first embodiment in which the coupler adaptor is 
threadably connected to the container assembly 10, FIG. 1 shows that the 
container assembly 10 also includes a gas escape tube 20 which extends 
longitudinally through the cylinder 12. The gas escape tube 20 includes an 
inlet 22 located above the liquid carbon dioxide contained in the cylinder 
12 to provide an exit for only the gaseous carbon dioxide and not the 
liquid carbon dioxide. Whenever the cylinder 12 is used in the inverted 
configuration, the escape tube 20 is utilized. Conversely, no gas escape 
tube 20 is included when the cylinder 12 is positioned in an upright 
state, as illustrated in FIG. 2, since the gaseous carbon dioxide is in 
the upper portions of the cylinder 12 immediately adjacent the coupling 
assembly 14 for release from the cylinder 12. 
Referring to FIG. 6, as well as FIGS. 3, 4 and 5, the gas escape tube 20 is 
integrally joined to a housing 24 of the valve assembly 26. The housing 24 
is threaded for secure attachment to the neck 16 of the cylinder 12. An 
O-ring seal member 28 is positioned adjcent the top surface of the neck 16 
to prevent leakage of the pressurized gas from the cylinder 12 through the 
threaded junction of the housing 26 and cylinder neck 16. 
A bore 30 is formed through the center of the housing 26 for communication 
with the previously discussed coupler adaptor 32. The coupler adaptor 32 
is fixedly joined to the housing 24 by means of interconnecting threads 
while an O-ring seal member 34 prevents leakage of gas through this 
threaded connection. 
In the embodiment of FIGS. 3, 4, 5 and 6 the check valve 36 of the valve 
assembly 26 is operatively positioned within a coupler passageway 38 of 
the coupler adaptor 32. The check valve 36 includes the check valve stem 
40, previously discussed in connection with the forces acting thereon, a 
valve plunger 42, and a valve spring 44. The valve stem 40 is integrally 
joined to the valve plunger 42 while the valve spring 44 is in operative 
engagement with the valve plunger 42. When the check valve 36 is closed, 
as seen in FIG. 4, the valve seat 46 acts to prevent the escape of gas 
from the cylinder 12. An O-ring seal 48 is located in the coupler 
passageway 38 around portions of the valve stem 40 to prevent escape of 
gas from the coupler adaptor 32 along the outer wall of the valve stem 40 
whenever the check valve 36 is in its opened position. 
The coupler adaptor 32 includes a generally cylindrical body 50 and an 
interface passage 52 which is formed perpendicular, or substantially 
perpendicular, to the coupler passageway 38 for providing a transverse 
flow of pressurized gas. A first circular groove 54 is formed in the 
coupler adaptor 32 at a first side of the interface passage 52 or located 
vertically above the interface passage 52 when the cylinder 12 is 
inverted. A second circular groove 56 is formed in the coupler adaptor 32 
at a second side of the interface passage 52 or located vertically below 
the interface passage 52 when the cylinder 12 is inverted. A first O-ring 
seal member 58 is seated in the first groove 54 while a second O-ring seal 
member 60 is seated in the second groove 56. 
The first and second O-ring seal members 58, 60 provide two functions 
critical to the proper operation of the present invention. In particular, 
whenever a coupling device of the coupling assembly 14 is joined to or is 
in operative association with the coupler adaptor 32 and engages the check 
valve 36 for releasing the pressurized gas from the cylinder 12, the first 
and second O-ring seal members 58, 60 function to balance the pressure 
present at the interface or area along which the pressurized gas escapes 
the coupler adaptor 32. As a result, the joined coupling device remains 
attached to the coupler adaptor 32. The balanced pressure results because 
the force of the escaping gas against the first O-ring seal member 58, 
acting to separate the coupler adaptor 32 and the coupling device, is 
balanced or offset by an equal force applied by the escaping gas in the 
opposite direction against the second O-ring seal member 60. In addition 
to the providing of balanced pressure along the exit interface of the 
coupler adaptor 32, the two O-ring seal members 58, 60 also function to 
prevent leakage of the gas so that the gas released from the cylinder 12 
will properly pass to the operatively connected coupling device. The 
O-ring seal members 58, 60 also provide friction force to help keep the 
coupler adaptor 32 joined with a mating recess, as will now be discussed. 
To provide a safety vent for pressurized fluid contained in the cylinder 
12, a burst disc assembly 108 is connected to the housing 24. The burst 
disc assembly 108 includes a vent plug 110, a rupture disc 112 and a seal 
114. The vent plug 110 is threadably fastened to the housing 24 in a 
recess formed in the housing 24. The seal 114 prevents leakage of the 
pressurized gas around the rupture disc 112 or through the threaded joint. 
The rupture disc 112 will rupture and permit the escape of the gas if an 
excessively high pressure is present within the cylinder 12. This is a 
required safety device and is desirable to prevent over-pressurization of 
the cylinder 12. 
In the preferred embodiment of the present invention, the coupling device 
referred to above is a pressure regulator assembly 62. Basically, the 
pressure regulator assembly 62 regulates or controls the pressure of the 
gas received from the cylinder 12 through the coupler adaptor 32. The 
pressure regulator assembly 62 includes an outlet port 64 formed in a 
regulator body 66. The outlet port 64 is connected to the outlet tube 18. 
The outlet tube 18 carries the pressure regulated carbon dioxide gas to 
the container which houses the liquid. As best seen in FIG. 5, the 
regulator body 66 also has a recess 68 formed therein. A cylindrical valve 
lifting pin 70 is integral with the regulator body 66 and extends into the 
recess 68. A vent passage 72 is also formed in the regulator body 66. The 
coupler adaptor 32 is slidably fitted or plugged into the recess 68 in 
order to couple the coupler adaptor 32 to the pressure regulator assembly 
62. The force necessary to plug the coupler adaptor 32 into the recess 68 
must be of a magnitude to overcome the pressurized gas force acting on the 
check valve 36. This force can readily and manually be overcome by simply 
inserting the coupler adaptor 32 into the recess 68 and then pressing 
downwardly (in those instances in which the cylinder 12 is in its inverted 
position). The vent passage 72 permits the escape of air from between the 
surface of the coupler adaptor 32 and the recess 68 when the coupler 
adaptor 32 is inserted into the recess 68. 
The pressure regulator assembly 62 further includes a regulator spring 
housing 74. A diaphragm 76 is located at the interface of the regulator 
spring housing 74 and the regulator body 66. A diaphragm back up plate 78 
engages one side of the diaphragm 76 while a diaphragm rivet 80 contacts 
the other or pressure side of the diaphragm 76. The head of diaphragm 
rivet 80 is positioned within a valve chamber 82 of the regulator body 66. 
A forward plate 84 is threadably fastened to an end of the regulator 
spring housing 74 and a regulator spring 86 is operatively positioned 
between the diaphragm back up plate 78 and the forward plate 84. 
Positioned within a cavity 88 formed in the regulator body 66 is a valve 
mechanism 90 which includes a bushing 92, a valve arm 94, a valve seat 96 
and a helical spring 98. The valve arm 94 moves laterally in a valve 
passageway 100 formed in the bushing 92. The valve arm 94 is in operative 
engagement with the helical spring 98 at one end of the helical spring 98. 
The opposite end of the helical spring 98 is joined to a rigid filter disc 
102 at the opposite end of the valve passageway 100. The filter disc 102 
is typically made of a porous material such as sintered bronze and which 
is fitted into a recess formed in the end of the bushing 92. The opposite 
side of the filter disc 102 communicates with a regulator passage 104. The 
regulator passage 104, in turn, communicates with the interface passage 
52. An O-ring seal 106 is positioned adjacent the bushing 92 and filter 
disc 102 to prevent the leakage of gas through the outer wall of the 
bushing 92. 
Finally, a safety shroud 116 is fixedly attached between the outer surface 
of the neck 16 and the housing 24. The safety shroud 116 is generally 
bowl-shaped, as seen in FIG. 1, having a wall 118 which surrounds the 
coupler assembly 14 and valve assembly 26. The safety shroud 116 is 
preferably made of a material having a melting point at a desired 
temperature. If the safety shroud 116 shows signs of excess temperature, 
it is an indication that the temperature of the environment about the 
safety shroud 116 and cylinder 12 has been at an undesirable level. Thus, 
the distortion of the safety shroud 116 is a warning that the temperature 
of the cylinder 12 may have been high enough to have annealed and weakened 
the metal cylinder 12 to produce an unsafe operating condition. 
Additionally, the safety shroud 116 acts to protect the coupling assembly 
14 and valve assembly 26 should the container assembly 10 and coupler 
adaptor 32 be inadvertently dropped during transport or during the 
interconnection of the coupler adaptor 32 and pressure regulator assembly 
62. 
In operation of the embodiment of FIGS. 1, 3, 4, 5, and 6, the housing 24 
is threadably joined to the cylinder 12 and the coupler adaptor 32 is also 
threadably joined to the housing 24. The cylinder 12 then receives carbon 
dioxide under pressure through the coupler adaptor 32. When it is desired 
to use the gaseous carbon dioxide for carbonation purposes, for example, 
the cylinder 12 is inverted and the pressure regulator assembly 62 is 
joined to the coupler adaptor 32 by inserting or slidably fitting or 
plugging the coupler adaptor 32 into the recess 68 formed in the pressure 
regulator assembly 62. In so doing, the valve stem 40 contacts the 
cylindrical valve lifting pin 70 which extends into the recess 68. The 
force exerted by the valve lifting pin 70 against the valve stem 40 moves 
the valve plunger 42 away from the valve seat 46 against the force of the 
valve spring 44 and the pressure force acting on the check valve 42. As a 
result, the pressurized carbon dioxide gas is able to pass from the valve 
passageway 38 through the opening created at the valve seat 46 into the 
interface passage 52. The gas is unable to escape around the valve stem 40 
because of the O-ring seal 48. 
As previously discussed, balanced forces are provided at the juncture of 
the coupler adaptor 32 and the pressure regulator assembly 62 by means of 
and the location of the first and second O-ring seal members 58, 60. The 
gas escaping the interface passage 52 and entering the pressure regulator 
assembly 62 exerts equal and opposite forces against the first and second 
O-ring seal members 58, 60. That is, the force tending to separate the 
pressure regulator assembly 62 from the coupler adaptor 32 in an upward 
direction is balanced by the force tending to separate the pressure 
regulator assembly 62 from the coupler adaptor 32 in a downward direction. 
As a consequence, the pressurized gas exiting the interface passage 52 and 
entering the regulator passage 104 does not tend to separate the coupler 
adaptor 32 from the pressure regulator assembly 62. 
Upon entering the regulator passage 104, the gas moves through the filter 
disc 102 into the valve passageway 100. The gas passes by the valve seat 
96 into the valve chamber 82 where it exerts pressure against the side of 
the diaphragm 76 and escapes the pressure regulator assembly 62 through 
the outlet port 64. The pressure of the gas entering the pressure 
regulator assembly 62 is controlled by the operation of the valve 
mechanism 90 and the diaphragm 76. The force of the gas against the 
diaphragm 76 causes the diaphragm 76 to move towards the left (as viewed 
with respect to FIG. 3) against the force of the regulator spring 86. At a 
predetermined gas pressure in the valve chamber 82 acting against the 
diaphragm 76, the diaphragm 76, as well as the diaphragm rivet 80, move 
laterally to the left a sufficient distance such that the valve arm 94 
contacts the valve seat 96 to thereby cut off the flow of the gas from the 
valve passageway 100. When the pressure is reduced below the predetermined 
pressure, the force of the regulator spring 86 moves the diaphragm 76 
laterally towards the right, as viewed with respect to FIG. 6, to permit 
the flow of gas past the valve seat 92 and into the valve chamber 82 so 
that it can pass through the outlet port 64 and then to the container 
which houses the beverage to be pressurized or carbonated. 
Referring now to the embodiment illustrated in FIG. 7, a connector body 120 
is threadably fastened to the neck 16 of the cylinder 12, while the O-ring 
seal member 28 is positioned at the interface of the neck 16 and the 
connector body 120 to prevent the escape of gas through this threaded 
joint. A valve housing 122 is threadably fastened to the connector body 
120 in a recess formed therein. A first O-ring seal 124 is positioned at 
one end of the threaded connection between the connector body 120 and the 
valve housing 122 and a second O-ring seal 126 is positioned at the 
opposite end of the threaded connection between the connector body 120 and 
the valve housing 122 to prevent escape of the gas through the ends of 
this threaded joint. 
A check valve 128 is provided in a recess formed in the valve housing 122. 
The check valve 128, like the check valve 36, includes a valve stem 130, a 
valve plunger 132 and a valve spring 134. A valve passageway 136 receives 
pressurized gas from the cylinder 12 and carries it to a first transverse 
passage 138 when the check valve 128 is in its open position. A second 
transverse passage 140 is also formed in the valve housing 122 and 
communicates with the first transverse passage 138 through the slot 142. 
In this embodiment, a coupler adaptor 144 is fixedly joined to a coupling 
device or, in the preferred embodiment, a pressure regulator assembly 146, 
unlike the embodiment illustrated in FIGS. 3, 4, and 6 in which the 
coupler adaptor 32 is threadably attached to the housing 24 of the valve 
assembly 26. Like the coupler adaptor 32, the coupler adaptor 144 includes 
a generally cylindrical body 148 and a transversely formed interface 
passage 150 for receiving the pressurized carbon dioxide gas whenever the 
valve plunger 132 is displaced away from a valve seat 152. Correspondingly 
also, the coupler adaptor 144 includes the first and second grooves 154, 
156, respectively, into which first O-ring seal member 158 and second 
O-ring seal member 160 are, respectively, seated. The first and second 
O-ring seal members 158, 160 provide balanced fluid forces adjacent the 
coupler adaptor 144 and valve housing 122 interface when the carbon 
dioxide gas exits the valve housing 122 and enters the coupler adaptor 
144. As a result, the coupler adaptor 144 and valve housing 122 remain in 
operative association when the check valve 128 is engaged and the carbon 
dioxide gas escapes the cylinder 12 past the valve plunger 132 of the 
check valve 128. The coupler adaptor 144 further includes a coupler 
passageway 162, which is in communication with the interface passage 150. 
The carbon dioxide gas, therefore, exits the interface passage 150 and 
enters the coupler passageway 162. From the coupler passageway 162, the 
gas flows to the pressure regulator assembly 146. 
In joining the coupler adaptor 144 to the valve housing 122, the coupler 
adaptor 144 is inserted or slidably fitted into a recess formed in the 
valve housing 122 so that the top surface 164 of the coupler adaptor 144 
engages the valve stem 130 of the check valve 128 in order to permit the 
flow of the gas into the first transverse passage 138. A vent passage 166 
formed in the coupler adaptor 144 is provided to permit the escape of air 
between the interface of the top surface 164 of the coupler adaptor 144 
and the valve housing 122 when the coupler adaptor 144 is inserted into 
the valve housing recess. 
Like the embodiment of FIG. 6, the gas passes from the coupler passageway 
162 to a regulator passage 168 formed in the pressure regulator assembly 
146. The remaining elements of the pressure regulator assembly 146 are 
identical in structure and function to the previously described pressure 
regulator assembly elements so that the previous description with respect 
to the pressure regulator assembly 62 also applies to the pressure 
regulator assembly 146. 
In view of the foregoing description, numerous advantages of the present 
invention are readily discerned. A coupler adaptor is provided for use 
with a valve to permit the release of a pressurized gas from a cylinder 
without the necessity of any additional retaining structure. The 
pressurized gas is released through the valve and the forces tending to 
separate the coupler adaptor from a body joined thereto are balanced. In 
this regard, the coupler adaptor is easily plugged into a recess formed in 
a valve housing or a pressure regulator assembly in order to open the 
valve and release the gas. The present invention is particularly 
advantageous in a beverage dispensing system in which it is desirable to 
quickly and efficiently replace a carbon dioxide-containing cylinder when 
the carbon dioxide has been expended from the cylinder. Additionally, it 
is equally important that the present invention provides an effective 
carbonation system with minimal parts in order to reduce the complexity of 
the system as well as to minimize the space needed for an operable 
carbonation system. 
Although the present invention has been described with reference to a 
limited number of embodiments, it is readily appreciated that variations 
and modifications can be effective within the spirit and scope of this 
invention.