Note: Descriptions are shown in the official language in which they were submitted.
~2~91 01~
1 A FLOW CHECK PREVENTION MECHANISM
Field of the Invention
This invention relates to a slow check prevention mechanism
and more particularly to a female coupler with a flow check
prevention mechanism for preventing closure of a male coupler
which is inserted into the female coupler should a vacuum occur
in the female coupler and fluid flow through the male coupler
and out of the female coupler is momentarily blocked.
Background of the Invention
Numerous female couplers are currently available for
coupling to and uncoupling from a pressurized or non-pressurized
male coupler. Such couplers are used extensively in hydraulic
hook-ups such as are used in agricultural and industrial
vehicles. U.S. Patent 4,303,098, entitled "Female Coupler"
which issued on 1 December 1981 to the assignee, describes a
similar coupler. In using a pair of the above-identified
couplers, wherein one coupler serves to direct fluid from a
pressurized supply source to one end of a hydraulic cylinder and
the second coupler receives flow from the opposite end of the
hydraulic cylinder and routes it to a sup, a problem occurs
when fluid flow through the female couplers is intentionally
blocked by closing a directional control valve associated with
the second female coupler. Under these conditions, fluid flow
; into and out of the hydraulic cylinder is non-existent although
the piston within the cylinder can fluctuate to a small extent.
This fluctuation of the piston within the cylinder is caused by
the implement, to which the cylinder is attached, being worked
over uneven ground. As the piston fluctuates, the fluid on one
side of the piston is compressed while the fluid on the opposite
side of the piston experiences a pressure drop or vacuum. The
pressure drop or vacuum is conveyed to the respective female
coupler and results in a situation in which the fluid contained
in the female coupler flows outward towards the hydraulic
cylinder. This creates a vacuum within the main cavity. As
this occurs, the main valve positioned in the female coupler
moves left ward allowing the male check ball to close upon a
sudden surge of return oil from the hydraulic function. Once
the male check ball is closed, a block is formed in the system
which presents problems once the directional control valve(s)
are again reopened. For example, as the directional control
I
1 valves are reopened, pressurized fluid is allowed to pass
through the first female coupler to the head end of the
hydraulic cylinder. However, the piston within the cylinder
will be unable to move because the fluid on the row end of the
piston will be blocked from flowing through the second female
coupler due to the closed male check ball. Up until now, the
only way the operator could correct this problem was to first
reverse the flow thereby opening the male check ball associated
with the rod end of the hydraulic cylinder and then again
lo reversing the flow such that the flow would be directed to the
head end of the hydraulic cylinder.
Now, a female coupler has been invented which overcomes this
problem by using a flow check prevention mechanism to prevent
the male check valve from closing should a vacuum occur in the
second female coupler when fluid flow through the male coupler
and out of the female coupler is momentarily blocked.
Summary of the Invention
Briefly, this invention relates to a flow check prevention
mechanism which is especially useful in a female coupler. The
flow check prevention mechanist prevents closure of a male
coupler which is coupled to the female coupler should a vacuum
occur in the female coupler when fluid flow through the male
coupler and out of the female coupler is blocked. The female
coupler includes a housing having a bore formed therein.
Positioned within the bore is a receptacle having a main cavity
joined by a passageway to an engagement bore which is located at
one end thereof. The male coupler is engage able into the
engagement bore. The receptacle also has a valve seat formed
about the periphery of the passageway and first and second ports
which communicate with the main cavity. Positioned within the
main cavity is a main poppet valve which controls the fluid flow
through the passageway. The main poppet valve has an internal
passage formed therein which provides fluid communication
between the first and second ports and has a valve stem which
extends outward from one end and projects through the passageway
into the engagement bore when the main poppet valve is in a
closed position. A second poppet valve is also present which is
located in the second port for controlling fluid flow
therethro~gh.
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1 The receptacle and the secondary poppet valve are linearly
moveahle by a lever-actuated cam which is pivotal attached to
the housing. The cam contains a pair of lobes, one of which
contacts an end of the receptacle and the second of which
contacts an end of the secondary poppet valve. As the first
lobe contacts and moves the receptacle, engagement balls located
about the periphery of the engagement bore are axially moved
thereby allowing coupling or uncoupling of a male coupler. As
the second lobe contacts the secondary poppet, fluid present
within the main cavity is allowed to be drained to sup.
The female coupler also includes a piston which is movably
positioned in the main cavity between the first and second ports
and a collar member which limits the overall travel of the main
poppet valve. The piston has a first end against which fluid
can impinge and a second end which contacts a portion of the
main poppet valve. The piston is actuated by fluid pressure so
as to assist in moving the main poppet valve against excessive
pressure contained in the male coupler thereby causing the male
check member to open. Lastly, the female coupler includes a
flow check prevention valve positioned within the main cavity
between the first and second ports. The flow check prevention
valve includes a hollow poppet having a first valve seat formed
adjacent to one end which is mutably with the piston. second
valve seat is also formed at an opposite end of the hollow
poppet and serves as a seat for a mutably check ball. The
check ball prevents the flow through the hollow poppet to the
first end of the piston while permitting flow in the reverse
direction when the fluid in the left end of the main cavity
increases in pressure due to thermal expansion. First and
second springs are also positioned on opposite sides of the flow
check prevention valve with the first spring acting to bias the
first valve seat against the piston while the second spring acts
to bias the check ball against the second valve seat. The flow
check prevention checks fluid flow in one direction at a
predetermined pressure value and relieves Fluid from the left
end of the main cavity at a higher pressure. By always
maintaining an equal or greater pressure on the first end of the
piston, relative to the pressure in the remainder of the main
cavity, the male check member will be prevented from closing
when a vacuum exists in the main cavity of the female
1 coupler and fluid flow through the male coupler and out of the
female coupler is momentarily blocked
The general object of this invention is to provide a flow
check prevention mechanism. A more specific object of this
invention is to provide a female coupler with a flow check
prevention mechanism which prevents closure of a coupled male
coupler should a vacuum occur in the female coupler and when
fluid flow through the male coupler and out of the female
coupler is momentarily blocked by a directional control valve.
Another object of this invention is to provide a female
coupler with a flow check prevention mechanism which includes a
flow check ball which permits the relief of fluid from the left
end of the main cavity when the fluid increases in pressure due
to thermal expansion.
Still further, an object of this invention is to provide a
flow check prevention valve which checks flow in one direction
at a low pressure and relieves fluid in an opposite direction at
a higher pressure.
Other objects and advantages of the present invention will
become more apparent to those skilled in the art in view of the
following description and the accompanying drawings.
Brief Description of the Drawings
Fig. 1 is a sectional view of a female coupler with a flow
check mechanism showing a male coupler coupled thereto and
having its main valve in an open position.
Fig. 2 is a sectional view of the female coupler shown in
Fig. 1 having the main valve in a closed position and showing an
alternative lever arrangement.
Fig. 3 is an enlarged side view of the secondary valve.
Fig. 4 is an enlarged left end view of the secondary valve
shown in Fig. 3.
Detailed Description of the Preferred Embodiment
L
Referring to Fig. 1, a female coupler 10 is shown which is
coupled to a male coupler 12. Such couplers 10 and 12 are
common features on agricultural tractors wherein they are
normally arranged in pairs to provide a hydraulic connection
between a fluid supply source and both ends of a working
cylinder. For purposes of convenience, and not by way of
limitation, the viewers right will be taken as the right-hand
side of the female coupler 10.
1 The female coupler 10 includes a housing 14 having a bore 16
formed therein. Preferably, the bore 16 is open at each end.
Movably positioned within the bore 16 is a receptacle 18 which
contains a Cain cavity 20 and a passageway 22 which opens into
an engagement bore 24. Preferably, the main cavity 20 is
centrally located within the receptacle 18 while the engagement
bore 24 is located at the right end thereof. Fluid can be
directed into and out of the main cavity 20 through a first port
26 and a second port 28. The first port 26 communicates with a
conduit 30 which has a directional control valve 32 positioned
there across. The directional control valve 32 regulates the
flow of pressurized fluid into, and sometimes out of, the main
cavity 20. us indicated in Figs. 1 and 2, the first port 26 can
be either a single port or a plurality of ports formed in the
periphery of the receptacle 18. While the first port 26 will
permit fluid flow in either direction, the second port 28 is
primarily an outlet port which permits fluid flow out of the
main cavity 20 out to a reservoir trot shown). The fluid which
enters the reservoir can then be recycled and used within the
hydraulic circuit.
Referring now to the male coupler 12, which is insertable to
the engagement bore 24, one will notice that it includes a male
cheek member 34. The male cheek member 34 consists of a check
ball 36, a compression spring 38, a stop 40 and a valve seat 42,
with the ball being located between the seat 42 and the stop 40
and normally being biased to a closed position against the seat
42 by the spring 38. The male check member 34 is attached to
the end of a hydraulic hose which in turn is connected to a
hydraulic function, such as one end of a hydraulic cylinder
having a movable piston therein. Movement of the piston within
the cylinder causes fluid flow through the hydraulic hose. It
should be noted that the stop 40 serves to limit the ruptured
movement of the check ball 36~
Positioned within the main cavity 20 is a movable main valve
46 which is preferably a poppet valve. Formed on the right-hand
end of the main valve 46 is a stem 48 which projects through the
passageway 22 and into the engagement bore 24 when the main
valve 46 is in a closed position as shown in Fig. 2. Positioned
just to the left of the stem 48 and formed in the periphery of
the main valve 46 is a beveled surface 50 which mates with an
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1 interior valve seat 52 formed adjacent to the left peripheral
surface of the passageway 22. When the beveled surface I is
seated against the interior valve seat 52, the passageway 22 is
blocked. In the blocked position, the main valve 46 is in its
right-most position as indicated in Fig. 2. The main valve 46
also includes an internal passage 54 which provides fluid
communication between the first port 26 and the second port 28.
To the left of the main valve I is the second port 28 which
is preferably circular in cross section and which is axially
aligned with the elongated central axis of the receptacle 18.
This second or outlet port 28 is constructed in an end member 56
which has an annular tapered outer surface 57 which is shown
being held against a similarly tapered inner surface 58 of the
receptacle 18 by a snap ring 60. Other methods of fastening the
end member 56 to the receptacle 18 can also be used. The second
port 28 is formed having two different internal diameters 6Z and
64 which are interconnected by an inclined or slanted surface
66. The smaller of the two internal diameters 64 is located in
the left or outer portion of the end member 56.
A secondary valve 68 is positioned in the second port 28 and
is movable between an open and a closed position. The secondary
valve 68, which is preferably a poppet valve, is best seen in
Figs. 3 and 4 and is of a complex configuration. As shown, the
right-hand end of the secondary valve 68 is in the form of a
head including a flat right-hand surface 70 from which an
elongated pin 71 extends rightwardly. right half portion of
the head of the secondary valve 68 is preferably triangular in
cross section and has rounded corners 72, see Fig. 4. Blending
with and extending leftwardly from the corners 72 is a circular
tapered section 74 which narrows into an elongated triangular
stem 76. The tapered section 74 forms a mating surface with the
slanted surface 66 formed on the end member 56. It should be
noted that although the elongated stew 76 and the flat right-
hand surface 70 have a triangular cross-sectional configuration,
other configurations are also feasible.
Positioned within the main cavity 20 between the first and
second ports, 26 and and 28 respectively, is a movable piston
78. The piston 78 has a sleeve-type configuration which is in
slid able contact with the outer periphery of the main valve I
and with the inside surface of the receptacle 18. The piston 78
1 has a left-hand end surface 80 and a right-hand end surface 82.
Positioned on the inner circumference of the movable piston 78
is a beveled surface 84 and a shoulder 86. As fluid flows
through the inner passage 54 of the main valve I it is brought
in contact with and impinges on the left-hand surface By of the
piston 78 thereby causing the piston 78 to move ruptured. The
extent of ruptured movement of the piston 78 is limited by a
step 88 formed on the inner periphery of the receptacle 18 while
left ward movement of the piston 78 is limited by contact with
the end member 56.
A collar member 90 is also positioned within the main cavity
18 which encircles a portion of the main valve 46. The collar
member 90 has a right-hand end surface 92 and a left-hand end
surface 94. The rotund end surface 92 is in constant
contact with a compression spring 96 which encircles a portion
of the main valve 46. The compression spring 96 abuts a
retainer ring 98 which is positioned adjacent to an annular seal
100. The retainer ring fly and the seal 100 are preferably
positioned adjacent to the base of the stem 48. The left-hand
end surface 94 of the collar member 90 abuts a retainer ring 102
which is positioned in a groove 104 formed on the inner
circumference of the receptacle 18. The combination of the
compression spring 96 and the retainer ring 102 serves to limit
the travel of the collar member 90. In addition, the
compression spring 96 urges the Cain valve 46 to the right so
that the beveled surface 50 seats against the interior valve
seat 52 as shown in Fig. 2. The comparison spring 96 should be
constructed with a sufficient spring force to hold the main
valve 46 in a closed position thereby blocking fluid flow
through the passageway 22 when the male coupler 12 is not
inserted into the engagement bore 24.
As shown in Figs. 1 and 2, a vent 106 is provided in the
receptacle 18 to the left of the collar member go This vent
106 provides an escape for any fluid that may become trapped
between the piston 78 and the collar 90. Preferably, the fluid
which escapes through the vent 106 will be directed back to a
reservoir (not shown) such that it can be reused again.
The female coupler 10 also includes a flow check prevention
valve 108 which is positioned within the main cavity 20 between
the first and second ports, 26 and 28 respectively. The flow
~2Z~
1 check prevention valve 108 includes a hollow poppet valve 110
having a first valve seat 112 formed adjacent to one end which
is mutably with the beveled surface 84 formed on the piston
78. The flow check prevention valve 108 also has a second valve
seat 114 formed at an opposite end thereof. A check ball 116 is
mutably with the second valve seat 114 so as to relieve fluid
from the left end of the main cavity 20 through the interior
section of the hollow poppet valve 110. This relief action
occurs only when the fluid in the left end of the main cavity 20
increases in pressure above a predetermined value due to thermal
expansion. The flow check prevention valve 108 is biased within
the main cavity 20 by first and second springs 118 and 120,
respectively. The first spring 118, which has the higher spying
force, is sandwiched between the flat right-hand surface 70 of
the secondary valve 68 and an inner shoulder 122 of the hollow
poppet valve 110. The first spring 118 is prevented from
flexing a substantial amount by both the elongated pin 71, which
extends out of the secondary valve 68, and by the inner
circumference of the hollow poppet valve 110. The second spring
120 is positioned within the internal passage 54 of the main
valve 46 and is sandwiched between an end surface 124 of the
passage 54 and the check ball 116. The flow check prevention
valve 108 is normally biased to a closed position wherein the
first valve seat 112 mates with the beveled surface 84 and the
check ball 116 is resting on the second valve seat 114 thereby
blocking fluid flow therethro~gh.
The flow check prevention valve 108 functions to assure that
the pressure impinging on the left-hand end surface 80 of the
piston I will always be either equal to or treater than the
fluid pressure within the remainder of the main cavity 20. This
is accomplished by allowing fluid to flow through the passage 54
into the left end of the main cavity 20 and then trapping this
fluid so as to limit the left ward movement of the main poppet
valve 46 after the passage 22 is opened. Should the fluid in
the left end of the main cavity 20 increase in pressure due to
thermal expansion, the check ball 116 will be lifted off its
seat 114 and allow some of the pressurized fluid to escape. It
should be noted that the force needed to open the check ball 116
is much higher than the force which can be built-up in the left
end of the main cavity merely by moving the main poppet valve 46
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lug
1 left ward. This assures that the check ball 116 will relieve
pressurized fluid that increased in pressure due to thermal
expansion.
The ability of the check ball 116 to relieve pressurized
fluid from the left end of the main cavity 20 should thermal
expansion or transient pressure spikes rise above a desirable
pressure limit insures that the gemming action of the lever 156
will open the secondary poppet valve 68. If the pressure in the
left end of the main cavity 20 would increase due to thermal
expansion and should no means be provided for relieving the
increased pressure, then the secondary poppet valve 68 would not
open and the male coupler 12 would be ejected under pressure
from the engagement bore 24.
my having the flow check prevention valve 108 in the female
coupler 10 and constructing it such that it checks the left ward
flow of fluid at a lower pressure valve than the value at which
it relieves the ruptured flow of fluid, it assures that the
male check ball 36 will not be closed by any pressure surges at
any time while it is coupled to the female coupler. This is
important for it means that should the directional control valve
32 be momentarily closed while the passage 22 is open and at a
time when a vacuum occurs in the main cavity 20 of the female
coupler 10, the main check balls 36 will not close against its
seat 42. The passage 22 between the female and male couplers,
10 and 12 respectively, will remain open because the male check
ball 36 will not be able to force the main valve 46 to the left
due to the pressure impinging on the left-hand surface 80 of the
piston 78. By using the flow check prevention valve 108 in each
of the pair of female couplers 10l one can be assured that once
the directional control valves 32 for each female coupler 10 is
moved to an open position, irregardless of the direction of
flow, fluid will be able to be directed into or out ox the
hydraulic function.
Positioned circumferential about the rotund end of the
receptacle 18 is an attachment device 126. This attachment
device 126 serves to hold the male coupler 12 in the engagement
bore 24. The attachment device 126 includes a sleeve 128 having
an internal race 130. The sides of the race 130 are preferably
slanted to facilitate the acceptance of engagement balls 132
which are positioned in sockets 134 located in the rightmost
g _
I L63 4
1 extremity of the receptacle 18. The sleeve 128 is held secure
within the housing 14 by a shoulder 136 and by a snap ring 138.
A compression spring 140 is sandwiched between the sleeve
128 and a retainer ring 142. The retainer ring 142 is retained
in a groove 144 which is machined into the outer surface of the
receptacle 18. The retainer ring 142 normally abuts a shoulder
146 formed in the housing 14 due to the force of the compression
spring 140.
In order to move the receptacle 18 to the right against the
force of the compression spring 140, a lever-actuatable cam 148
is employed. This lever-actuatable cam 148 is pivotal secured
to the housing 14 by a pin 150 and includes first and second cam
lobes 152 and 154 and a lever arm 156. For the sake of
simplicity, the lever arm 156 will be described as initially
being positioned in the horizontal plane wherein it is capable
of being raised. By raising the lever arm 156 to the position
indicated by the dotted line in Fig. 1, the first cam lobe 152
will be brought into contact with the left end of the receptacle
18. As the first cam lobe 152 urges the receptacle 118 to the
right, the engagement balls 132 will roll partially out of the
sockets 13~ and into the race 1300 With the engagement balls
132 positioned in the race 130, an unobstructed path is provided
so that the male coupler 12 can be inserted into the engagement
bore 24. In this position, the compression spring 140 is
compressed and exerts a left ward force on the receptacle 18 via
the retainer ring 142. The receptacle 18 will therefore return
to its initial position once the lever arm 156 is lowered.
us the lever arm 156 is raised further, the second cam lobe
154 will contact the stem portion I of the secondary valve 68
and cause it to move ruptured to an open position. Preferably
the secondary valve 68 will open prior to the time that the
; engagement balls 132 move into the race 130. With the second
port 28 opened, any fluid which may be present to the left of
the check ball 116 can seep out. This assures that only a small
quantity of non-pressurized fluid will remain to the left of the
check ball 116 and therefore the main valve 46 will be free to
move left ward as the male coupler 12 is inserted into the
engagement bore 24. It should be noted that the operator is
able to insert the male coupler 12 with one hand while holding
the lever arm 156 upwards with the second hand. As the operator
-- 10 --
1 lowers the lever arm 156, the cam lobes 152 and 154 will move
left ward away from the receptacle I and the secondary valve
stem 76, respectively. The receptacle 18 will move left ward
simultaneously due to the force of the compression spring 140.
As the receptacle 18 moves left ward, the secondary valve 68 will
close due to the force of the springs 118 and 1~0 and the
engagement bells 132 will roll out of the race 130 and return to
the sockets 134. The engagement balls 132 will contact a lip
158 formed on the outer circumference of the male check member
34 and will sufficiently hold the male coupler 12 in the
engagement bore 24.
An alternative embodiment of a lever-actuatable cam 149 is
depicted in Fig. 2 wherein four cam lobes designated 152, 154,
160 and 162 are present. This embodiment allows two female
couplers 10 (only one of which is shown) to be actuated with
only one offset lever arm 156. With this arrangement, movement
of the lever arm 156 above the horizontal position will activate
the lower female coupler (shown) while movement of the lever arm
156 below the horizontal position will activate an upper female
coupler (not shown). Other arrangements and setups will be
apparent to those skilled in the art. The primary purpose of
the lever-actuatable cams 148 or 149, which incidentally can be
manually or automatically operated, is to facilitate the
coupling and uncoupling of the female coupler 10 to and from the
male coupler 12. The lever-actuatable cams 148 or 149 becomes
especially important when the male coupler 12 is in a
pressurized condition.
Numerous seals, such as O-rings and Teflon rings, are
utilized within the female coupler 10 to prevent leakage between
the various elements. These seals have not been discussed in
detail since their function is well-known to those skilled in
the art.
Operation
The procedure of coupling both a pressurized and a non--
pressurized male coupler to the female coupler 10 will now reexplained. This explanation will be given assuming that a pair
of female couplers 10 are connected by hydraulic hoses to
opposite ends of a hydraulic cylinder having a movable piston
therein. The coupling process will be directed to the female
coupler which is attached to the rod end of the hydraulic
-- 11 --
I I
1 cylinder. The fluid will be flowing from the rod end of the
hydraulic cylinder, through the female coupler 10 and into a
reservoir.
Coupling in a Non-Pressurized Situation
Jo couple a non-pressurized male coupler 12 to the female
coupler 10, the procedure is as follows. Starting with the main
valve 46 in a closed position, as depicted in Fig. 2, and with
the directional control valve 32 closed, so that no fluid can
flow out of the main cavity 20, the operator raises the lever
10 arm 156. This action causes the cam lobe 152 to contact the
left end of the receptacle 18 and start to push it to the
right. As the lever arm 156 is raised further, the second cam
lobe 154 will contact the stem 76 of the secondary valve 68 and
move it ruptured to an open position. This action allows any
fluid trapped in the main cavity 20 to exit to a sup. Further
raising of the lever arm 156 causes alignment of the race 130
with the sockets 134 thereby permitting the engagement balls 132
to roll partially into the race 130 so that the male coupler 12
will have an unobstructed path into the engagement bore 24. At
the same time, the spring 140 is compressed by the ruptured
movement of the receptacle 18 and it will exert a force on the
receptacle 18 to move it left ward as the lever arm 156 is
lowered.
The operator then inserts the male coupler 12 into the
engagement bore 24 with one hand as he holds the lever arm 156
in the raised position with the other hand. Once the male
coupler 12 is inserted, the operator holds it in place as he
lowers the lever arm 156 to its original position. This
lowering of the lever arm 156 causes the cam lobes 152 and 154
to move away from the receptacle 18 and the secondary valve 68,
respectively. Simultaneously, the spring 140 urges the
receptacle 18 left wards. As the receptacle 18 moves left ward,
the engagement balls 132 will roll back into the sockets 134 and
forceable contact the outer circumference of the male check
member 34, just to the right of the lip 158. This forceable
contact is sufficient to hold the male coupler in the engagement
bore 24.
As the male coupler 12 is inserted into the engagement bore
24, the stem 48 of the main valve 46, which is being urged to
the right by the spring 96, will contact the male check ball 36
12 -
~2~9~
1 and push it ruptured off its seat 42. The male check ball 36
will move ruptured compressing the spring 38 until it contacts
the stop 40. It should be noted that the force ox the spring 96
acting on the main valve 46 of the female coupler 10 is much
stronger than the force of the spring 38 acting on the male
check ball 36.
With the check ball 36 abutting the stop 40~ further
insertion of the male coupler 12 into the engagement bore 24
will cause the main valve 46 to move left ward compressing the
springs 96, 118 and 120. This left ward movement of the main
valve 46 causes the bevel surface 50 to move away from the
interior valve seat 52 thereby opening the passageway 22. Fluid
flow through the passage 22 will now be possible as soon as the
directional control valve 32 is open.
With the directional control valve 32 open, fluid will flow
both from the male coupler 12 through the first port 26 to a
reservoir and also through the passage 54 to the left end of the
main cavity 20. The fluid flowing into the left end of the main
cavity 2Q will be prevented from exiting through the outlet port
28 because the secondary valve 68 will be closed due to the
force of the springs 118 and 120. This means that the fluid
pressure in the left end of the main cavity will build to a
desirable value wherein it will urge the piston 78 ruptured
until it contacts the step 88. The flow check prevention valve
108 will already be biased retreads by the force of the spring
118 acting on the inner shoulder 122. Once the flow check
prevention valve 108 is seated at 112 against the bevel surface
84, no further flow Jill be allowed into the let end of the
main cavity 20. From this point on, all fluid will flow from
the male coupler 12 through the female coupler 10 to a
reservoir. The coupling process is therefore completed.
Uncoupling in a Non-Pressurized Situation
To uncouple a non-pressurized connection, the operator
closes the directional control valve 32 and raises the lever arm
156. The raising of the lever arm 156 partially moves the
receptacle 18 ruptured along with opening the secondary valve
68 thereby relieving fluid from the main cavity 20. Further
raising of the lever arm 156 move the receptacle 18 further
retreads and will allow the engagement balls 132 to roll into
the race 130 thereby releasing the force which was holding the
- 13 -
I
1 male coupler 12 in the engagement bore 24. As the operator
pulls the male coupler ruptured with one hand, the main valve
46 of the female coupler 10 will be urged to a closed position
by the force of the springs 96r 118 and 120. The operator then
lowers the lever arm 155 thereby closing the outlet port 28 and
the uncoupling process is completed.
Coupling in a Pressurized Situation
To couple the female coupler 10 to a pressurized male
coupler 12, the process differs in that the increased fluid
pressure in the male coupler 12 will prevent the male check ball
36 from initially moving away from the seat I
The procedure is as follows. The operator first closes the
directional control valve 32 and raises the lever arm 156
thereby partially moving the receptacle 18 to the right while
simultaneously opening the secondary valve 68. With the outlet
port 28 open, fluid is bled out of the main cavity 20. Further
raising of the handle 156 permits the male coupler 12 to be
inserted into the engagement bore 24 without being obstructed by
the engagement balls 132. As the male check ball 36 contacts
the main valve 46, it pushes the main valve 46 left wards while
remaining against the seat 42. This means that the male coupler
12 will be fully inserted into the engagement bore I while the
male check ball 36 is still seated against the seat 42. At the
same time, the main valve 46 is moved left ward wherein it abuts
the shoulder 86 of the piston 78 and drives it left ward. In
order to open the male check ball 36, pressure within the
receptacle 18 has to be increased. This is accomplished by
having the operator lower the lever arm 156 and then open the
directional control valve 32. The incoming fluid is then
permitted to flow through the passage 54 and around the first
valve seat 112 of the flow check prevention valve 108 to the
left end of the main cavity 20. As this fluid pressure
increases, it acts on the total surface 80 of the piston 78.
When the force of the fluid impinging on the surface 80~ along
with the force of the compression springs 96, 118 and 120,
exceeds the combined resistant forces of both the fluid
impinging on the right side of the male check ball 36, the force
of the spring 38 and the force of the fluid impinging on the
right end of the main valve 46, the main valve 46 will start to
move ruptured thereby moving the male check ball 36 off its
- 14 -
1 seat 42. This movement causes the passage 22 to be opened
thereby permitting flow from the female coupler 10 to the male
coupler 12.
It should be noted that the pressure required in the female
coupler 10 to create the above action is considerably less than
the internal pressure present in the male coupler 12.
Uncoupling in a Pressurized Situation
The uncoupling of a pressurized male coupler is the same as
that described above for the non-pressurized uncoupling
process.
Preventing Closure of the Male Check sell
Lowe operation of the flow check prevention mechanism 108
will now be described starting from a position wherein the rod
end of the hydraulic cylinder is connected to this particular
female coupler 10 and the directional control valve 32 is
closed. Such a situation normally occurs when the fluid
directed to the hydraulic function is cut off and the piston
within the hydraulic cylinder is at rest. In such situations,
the movement of the implement, to which the hydraulic cylinder
is connected, will cause the piston within the cylinder to move
a very small amount. Such movement creates a vacuum on the rod
end of the cylinder which causes a vacuum in the female coupler
10. Once the directional control valve 32, which is
associated with the head end of the hydraulic cylinder, is
opened, a pressure surge is created in the rod end which is
conveyed to the male coupler 12 such that the male check ball 36
tries to seat against its seat 42. This however, is not
possible with the present invention because the flow check
prevention valve 108 will not permit the escape of pressurized
fluid from the left end ox the main cavity 20. The only fluid
that can escape is that which has been increased in pressure due
to thermal expansion. It must be realized that the pressure
increase due to thermal expansion is five to eight times higher
than the maximum pressure that would be available in the male
coupler 12 to push the main valve 46 left ward. With an equal or
greater pressure always being present in the left end of the
main cavity 20, the main valve 46 will be essentially restrained
from moving left ward from the position depicted in Fig. 1. This
means that the male check ball 36 will be unable to seat against
its seat 32 and therefore the passage 22 will never be blocked
- 15 -
~22~
1 once the male coupler 12 is coupled to the female coupler 10.
While the invention has been described in conjunction with a
specific embodiment using two alternative lever-actuatable cam
arrangements, it is to be understood that many alternatives,
modifications, and variations will be apparent to those skilled
in the art in light of the foregoing description. Accordingly,
this invention is intended to embrace all such alternatives,
modifications, and variations which fall within the spirit and
scope of the appended claims.
