Quick disconnect fluid line coupling

The invention provides a quick disconnect fluid coupling for connection of fluid conduits and incorporates automatically actuated valves for closing the end of each fluid conduit when the connection is broken, and specifically provides for minimal fluid loss from the line at the time of making or breaking the connection.

FIELD OF THE INVENTION 
The invention relates to quick disconnect couplings for making and breaking 
connection between two fluid lines and has to do particularly with the 
type of coupling that incorporates automatically actuated valves for 
closing the end of each fluid conduit when the connection is broken. More 
specifically, the invention relates to that type of coupling in which 
minimal fluid is lost from the line at the time of making or breaking the 
connection. 
BACKGROUND PRIOR ART 
For reference to prior art couplings, attention is directed to the prior 
art Hengst U.S. Pat. No. 2,451,218, issued Oct. 12, 1948; the Main, Jr. 
U.S. Pat. No. 2,451,441, issued Oct. 12, 1948; the Main, Jr. U.S. Pat. No. 
2,457,251, issued Dec. 28, 1948 and the Hansen U.S. Pat. No. 2,548,528, 
issued Apr. 10, 1951. 
Attention is further directed to the Pearson U.S. Pat. No. 3,500,859, 
issued Mar. 17, 1970; the Hodson U.S. Pat. No. 3,196,897, issued July 27, 
1965; and the Collar U.S. Pat. No. 3,191,972, issued June 29, 1965. 
Attention is further directed to the Johnson U.S. Pat. No. 3,550,624, 
issued Dec. 29, 1970 and the De Visscher U.S. Pat. No. 3,777,771, issued 
Dec. 11, 1973. 
SUMMARY OF THE INVENTION 
The invention includes a fluid conduit coupling comprising first and second 
coupling members having means for connection to associated fluid conduits 
and means for connection to each other. The first coupling member includes 
a first body having therein a fluid flow passage, and means for 
selectively preventing fluid flow through the passage. The second coupling 
member includes a second body having therein a fluid passage, annular 
inner seal means housed in the second body fluid passage and adjacent one 
of the ends of the second coupling member, and means for selectively 
preventing fluid flow through the second body fluid flow passage. The 
fluid flow preventing means includes a movable valve sleeve housed in the 
fluid passage of the second body, one end of the movable valve sleeve 
including an annular sealing surface. The movable valve sleeve is movable 
between a first position wherein the annular sealing surface engages the 
annular inner seal means of the second body and a second position wherein 
the annular sealing surface is spaced from the annular inner seal means of 
the second body. The movable valve sleeve is engaged by the first coupling 
member and moved to the second position when the first and second coupling 
members are joined. The fluid flow preventing means also includes, a valve 
pin housed in the movable valve sleeve and having an end engagable with 
the first coupling member when the first and second coupling members are 
joined. The fluid flow preventing means also includes seal means supported 
on the end of the second valve pin and engagable in abutting relation with 
the movable valve sleeve, means for urging the seal means supported on the 
end of the second valve pin into engagement with the movable valve sleeve, 
and means for urging the movable valve sleeve into engagement with the 
annular inner seal means. 
The invention further includes a fluid conduit coupling comprising first 
and second coupling members having means for connection to associated 
fluid conduits and means for connection to each other. The first coupling 
member includes a body having a fluid flow passage therein and means for 
selectively preventing fluid flow through the fluid flow passage. The 
fluid flow preventing means includes a first sleeve housed in the passage 
and including an internal sealing surface, a first movable valve pin 
housed in the first sleeve, the first valve pin being movable from a fluid 
flow preventing position wherein an end of the first valve pin is in 
sealing relation with the internal sealing surface to a retracted position 
wherein the end of the first valve pin is spaced from the internal sealing 
surface to permit fluid flow through the first sleeve, and means for 
urging the first valve pin toward the fluid flow preventing position. The 
second coupling member includes a second body having a fluid passage 
therein, seal means housed in the second body fluid passage and adjacent 
one of the opposite ends of the second coupling member, and the seal means 
being adapted to surround the first sleeve for forming a seal therebetween 
as the first and second coupling members are joined. The second coupling 
member also includes means for preventing fluid flow through the second 
body fluid flow passage until the second coupling member seal means and 
the first sleeve form a seal therebetween. 
The invention also includes a fluid conduit coupling comprising first and 
second coupling members having means for connection to associated fluid 
conduits and means for connection to each other. The first coupling member 
includes a body having therein a fluid flow passage, and means for 
selectively preventing fluid flow through the passage including a first 
sleeve housed in the passage and having an internal sealing surface, a 
first movable valve pin housed in the valve insert sleeve, the first 
movable valve pin being movable from a fluid flow preventing position 
wherein an end of the first valve pin is in sealing relation with the 
internal sealing surface of a retracted position wherein the end of the 
first valve pin is spaced from the internal sealing surface to permit 
fluid flow through the first sleeve, and means for urging the valve pin 
toward the fluid flow preventing position. The second coupling member 
includes a second body having a fluid passage therein, seal means housed 
in the fluid passage adjacent one of the second coupling member ends and 
adapted to surround the first sleeve for forming a seal therebetween when 
the first and second coupling members are joined, and means for 
selectively preventing fluid flow through the second body fluid flow 
passage. The means for selectively preventing fluid flow through the 
second body includes a movable valve sleeve housed in the second body 
fluid passage, one of the ends of the movable sleeve including an annular 
sealing surface, the movable sleeve being movable between a first position 
wherein the annular sealing surface abuts the seal means in sealing 
relationship and a second position wherein the annular sealing surface is 
spaced from the sealing means, the movable sleeve being located to be 
engaged by the first sleeve in end-to-end abutting relationship and to be 
moved to the second position when the first and second coupling members 
are joined. The means for selectively preventing fluid flow through the 
second body also includes a second valve pin housed in the movable valve 
sleeve and having an end engageable with the first valve pin for forcing 
the first valve pin to the second position the first and second coupling 
members are joined, seal means supported on the ends of the second valve 
pin and selectively engagable in abutting relation with the movable valve 
sleeve to form a seal therebetween, means for urging the seal means 
supported on the end of the second valve pin into engagement with the 
movable valve sleeve, and means for urging the movable valve sleeve into 
engagement with the seal means housed in the fluid passage. 
Other features and advantages of the invention are set forth in the 
following description and claims and in the drawings.

DESCRIPTION OF A PREFERRED EMBODIMENT 
Illustrated in FIG. 1 is the engine housing 10 of an outboard motor 12. The 
outboard motor 12 is mounted on the transom 14 of a boat and is supported 
thereon by a pair of brackets 16 and 18. The outboard motor 12 is also 
connected to a fuel tank 20 by a fuel line 22. The fuel line 22 is joined 
at one of its ends to the outboard motor 12 by a quick disconnect coupling 
24 and at its opposite end to the fuel tank 20 by a quick disconnect 
coupling 26. 
In the illustrated construction, the quick disconnect couplings 24 and 26 
are identical and are shown in greater detail in FIGS. 2-4. As shown 
therein the quick disconnect couplings 24 and 26 each include a male 
coupling member 28 and a female coupling member 30. While in the 
illustrated construction the coupling members 28 are shown as being 
connected to the fuel line 22 and the coupling members 30 are connected to 
the outboard motor 12 and the fuel tank 20, in an alternative construction 
the coupling members 30 could be joined to the fuel line 22 and the 
coupling members 28 could be joined to the outboard motor and to the fuel 
tank. 
The coupling member 30 includes a body portion 32 having therein a stepped 
cylindrical bore 34. While the body portion 32 is shown in the illustrated 
construction as being comprised of a resilient material such as a 
thermoplastic, it could also be comprised of a plurality of other suitable 
materials including metal. The stepped cylindrical bore 34 includes 
stepped fluid passage portions 36 and 38 at one end of the body portion 32 
and an enlarged portion 40 for housing an end of the coupling member 28. 
Intermediate the bore portions 38 and 40 is an additional bore portion 42 
fixedly housing one end 44 of a valve insert sleeve 46, the valve insert 
sleeve 46 including an opposite end 48 projecting into the bore portion 40 
and having an end face 50 generally co-planar with an end face 52 of the 
body portion 32. The end 48 of the valve insert sleeve 46 and the end 
portion of body portion 32 surrounding it define an annular chamber 
therebetween for receiving an end of the coupling member 28. The valve 
insert sleeve 46 also defines a central longitudinal bore 54 which 
comprises a fluid passage communicating with the fluid passage portions 36 
and 38 of the bore 34. The projecting end 48 of the valve insert sleeve 46 
is thickened internally to provide to annular sealing surface having an 
inside diameter less than the inside diameter of the remainder of the 
central bore 54 of the fluid passage of the valve insert sleeve 46. While 
in the illustrated construction the valve insert sleeve 46 is an integral 
one-piece structure and is shown as being comprised of a flexible or 
elastomeric material, it should be understood that the valve insert sleeve 
could also be comprised of a metal sleeve supporting an inner resilient 
seal member to form the annular sealing surface 56 on the inside of the 
projecting end 48 of the valve insert sleeve 46. 
The coupling member 30 also includes means for selectively preventing fluid 
flow through the fluid passage 54 of the valve insert sleeve 46. This 
fluid flow preventing means includes amovable valve pin 58 housed in the 
fluid passage 54 in the valve insert sleeve 46 and being movable therein 
longitudinally. The movable valve pin 58 includes a seal supporting end 
having thereon an O-ring seal 60. The O-ring seal is held or restrained 
between an annular part on the valve pin 58 to the right of a plurality of 
longitudinally extending vanes 62 and an annular shoulder 64 surrounding 
the end of the valve pin 58. The O-ring seal 60 is adapted to abut the 
internal annular sealing surface 56 at the end of the valve insert sleeve 
46 and to thereby prevent fluid flow through the fluid passage 54 defined 
by the sleeve 46. 
Means are also provided for urging the movable valve pin 58 toward the 
sealing surface 56 and to cause abutting sealing engagement therewith of 
the O-ring 60. In the illustrated construction, this means comprises a 
helical compression spring 66 having one end engaging a shoulder 68 of the 
body portion 32 and another end engaging the movable valve pin 58. 
The coupling member 28 of each of the quick disconnect couplings 24 and 26 
includes a body portion 70 having a central stepped cylindrical bore or 
cavity 72. As in the case of the coupling member 30, though the body 
portion 70 is illustrated as being comprised of a resilient material, 
other suitable materials such as metal could also be employed. 
The coupling member 28 includes a pair of parallel abutting O-ring seals 74 
and 78 housed within a relatively large diameter portion 78 of the central 
stepped cylindrical cavity 72 adjacent one end of the body portion 70, the 
O-ring seals 74 and 76 being fixedly retained therein between an annular 
retaining ring 79 and a shoulder 80 of the body portion 70 of the coupling 
member 28. While O-ring seals 74 and 76 are illustrated, it is also 
contemplated that other suitable means such as a quad bone seal could be 
used as a suitable alternative. 
The coupling member 28 also includes a movable valve sleeve 82 slidably 
housed within a central portion 84 of the stepped cylindrical bore or 
cavity 72, the valve sleeve 82 being supported for movement longitudinally 
toward and away from the O-ring seals 74 and 76. In the illustrated 
construction, the end 88 of the movable valve sleeve 82 adjacent the 
O-ring seals 74 and 76 is provided with two annular mutually concentric 
sealing surfaces 86 and 90. The outer sealing surface 86 is provided by a 
peripheral shoulder portion 92 of the movable sleeve 82 and is adapted to 
engage the O-ring seal 76 in abutting relation as will be described 
hereinafter. The end of the movable valve sleeve 82 adjacent the O-ring 
seals 74 and 76 also includes an annular longitudinally projecting portion 
94 which faces and is engageable with the opposed annular end 50 of the 
valve insert sleeve 46 of the other coupling member 30. The end 88 of the 
movable valve sleeve 82 adjacent the O-ring seals 74 and 76 also includes 
an internally thickened portion 96 functioning to provide the inner 
annular shoulder forming the sealing surface 90. 
Means are also provided to selectively prevent fluid flow through the fluid 
passage 72 of the coupling member 28 when the coupling members 28 and 30 
are separated and to permit fluid flow through the coupling member 28 when 
the coupling members are forced together in coupling relationship. In the 
illustrated construction, the selective fluid flow preventing means 
includes a movable valve pin 98 which is housed in the stepped central 
fluid passage 72 of the valve body portion 70, which has an end 100 
extending through the central longitudinal bore 102 of the movable sleeve 
82, and which is adapted to engage the other coupling member 30. The end 
100 of the valve pin 98 includes a small diameter cylindrical portion 103 
adapted to support an O-ring seal 104, the O-ring seal 104 being 
restrained between an annular part on the valve pin 98 to the left of a 
plurality of longitudinally extending vanes 106 integral with the valve 
pin 98, and an annular flange 108 surrounding the end of the valve pin. 
The end of the valve pin 98 and the annular flange 108 also function to 
define a generally planar end surface 110 adapted to abut the opposed 
planar end 112 of the movable valve pin 58 of the coupling member 30 when 
the coupling members are forced together in coupling relation and to 
thereby force that valve pin to its retracted position wherein fluid flow 
through the coupling member 30 is permitted. 
Means are also provided for urging the movable valve sleeve 82 into 
engagement with the O-ring seal 104 surrounding the end of the valve pin 
98 and to thereby cause sealing engagement between the O-ring seal 104 and 
the internal surface 90 of the movable valve sleeve 82. This means 
comprises a helical compression spring 114 positioned between the forward 
annular face 115 of the annular flange 116 and a spring seat 117 on the 
movable valve sleeve 82. 
Means are further provided for biasing the movable valve sleeve 82 into 
engagement with the seal 76. This means comprises a helical compression 
spring 120 positioned between a shoulder portion 122 of the coupling 
member body portion 70 and rearward annular face 124 of the annular flange 
116 of the movable valve pin 98. 
Operation of the above described components during coupling of the coupling 
members 28 and 30 is illustrated in FIGS. 2 through 4. As illustrated in 
FIG. 2, when the coupling members 28 and 30 are separated, they provide 
sealed closures for the respective fluid conduits to which they are 
attached. More specifically, referring to the coupling member 30, the 
O-ring seal 60 supported by the end of the movable valve pin 58 is forced 
by the helical compression spring 66 into abutting engagement with the 
sealing surface 56 of the fixed valve sleeve 46 and thereby prevents fluid 
flow through the coupling member 30. Referring to the other coupling 
member 28, the helical compression spring 114 functions to maintain a 
sealing relationship between the O-ring seal 104 supported on the valve 
pin 98 and the sealing surface 90 of the movable valve sleeve 82. The 
second helical compression spring 120 functions to bias the movable valve 
pin 98 and the movable sleeve 82 toward the O-ring seal 76 to thereby 
maintain sealing engagement between the annular sealing surface 86 of the 
movable valve sleeve 82 and the O-ring seal 76. 
When the coupling members 28 and 30 are then moved into coupling engagement 
as shown in FIG. 3, as the body 70 of the coupling member 28 is inserted 
into the annular chamber 40 of the coupling member 30, the projecting end 
48 of the fixed valve sleeve 46 of the coupling member 30 is slidably 
received in sealing relation within the O-ring seal 74 and then abuts the 
end 88 of the movable valve sleeve 82. 
In the illustrated construction, the fixed valve sleeve 46 and the movable 
valve sleeve 82 are shown as being comprised of a plastic material. It 
should also be recognized that the valve sleeves could similarly be 
constructed of non-plastic materials such as metal. 
When the coupling members 28 and 30 are in the position shown in FIG. 3, a 
fluid-tight seal is formed between the external cylindrical surface of the 
fixed valve sleeve 46 and the internal sealing surface of the O-ring seal 
74. Accordingly, in this position a fluid-tight seal is formed between the 
coupling members 28 and 30 while the valve pins 58 and 98 and the 
associated seal structures contained within the coupling members 28 and 30 
still prevent fluid flow through the couplings. 
When the coupling members 28 and 30 are forced into further coupling 
engagement as shown in FIG. 4, movement to the right of the fixed valve 
sleeve 46 of the coupling member 30 will force the movable valve sleeve 82 
to the right and away from the O-ring seal 76. This movement to the right 
of the movable valve sleeve 82 causes increased compression of the helical 
coil spring 114 thereby overcoming the force of the second compression 
spring 120 and causing the movable valve pin 98 to move into engagement 
with the shoulder 130 of the coupling member body portion 70. Continued 
movement of the sleeve 44 inwardly of the member 28 serves to displace the 
sleeve 82 further to the right relative to the valve pin 98 and causes 
separation of the sealing surface 90 and the O-ring seal 104. At the same 
time, abutement of the surfaces 110 and 112 of the valve pins 98 and 58 
during continued movement to the right of the member 30, causes the O-ring 
60 to move to the left relative to the seal 56. Fluid is then permitted to 
flow through fluid passage 72 of coupling member 28 and along the vanes 
106, through the bore 102 of the sleeve 82, past sealing surface 90, past 
the sealing surface 56, through the bore 54, around the O-ring seals 104 
and 60, and then along the vanes 62 of the valve pin 58 and through fluid 
passage portions 38 and 36 of coupling member 30. 
When the coupling members 28 and 30 are subsequently disengaged, as shown 
in FIG. 3, the valve components of the coupling members will then return 
to positions in sealing engagement with complementary sealing surfaces to 
thereby prevent fluid flow from the coupling members. As the coupling 
members 28 and 30 are disengaged, the valve pin 98 is moved away from the 
pin 58 thereby permitting the O-ring seal 60 to engage the sealing surface 
56, and the sealing surfaces 86 and 90 will move into sealing engagement 
with the seal 76 and O-ring seal 104, respectively, as shown in FIG. 3. In 
this position a fluid seal is still maintained between seal 74 and the 
fixed valve sleeve 44. As the coupling members 28 and 30 are further 
separated, the end 48 of the fixed valve sleeve 44 is withdrawn from the 
seal 74. Since sealing engagement of the valve components of the coupling 
members occurs before the seal between the respective coupling members is 
broken, fluid loss when disconnecting the coupling members is minimal and 
there is no discharge of fluid under pressure during the disconnection. 
The only fluid allowed to escape upon disconnection is that left in the 
relatively small chamber 132 shown in FIG. 3. The design of the coupling 
members is such that the volume of that chamber 132 is minimal. 
While the illustrated construction shows a bayonette latch means for 
joining the coupling members, various other suitable means may be provided 
to permit easy engagement and disengagement of the coupling members and 
also to prevent accidental disengagement. 
One of the advantages of the disclosed coupling members is the inclusion of 
spring loaded abutting seals rather than sliding seals. Accordingly, the 
problems incident to sticking sliding O-ring seals and resultant leakage 
are avoided. 
Another of the advantages of the construction of the coupling members lies 
in the provision of movable valve pins which are supported between 
compression springs and wherein the longitudinal position of the valve pin 
98 is controlled by the relative compression of two opposed compression 
springs. Accordingly, the fluid-tight seal between the movable sleeve and 
the O-ring seal can be abutting seals and the seal between the sleeve and 
the O-ring seal of the coupling member body are also abutting seals. 
Additionally, this construction also eliminates the effect of both linear 
tolerance stack-up and concentricity problems. 
Various features of the invention are set forth in the following claims.