Field
[001] This application relates to an oil controlled valve.
Background
[002] Hydraulic valves have difficulty responding quickly between the on and
off position during applications requiring a high rate of flow. Even if the valve can
respond quickly, the flow paths containing fluid can slow the operation down if the
paths contain air pockets or inadequate pressure. As such it is difficult to keep the
flow paths primed before the valve switches between the off and on position. This
presents an even greater challenge during operations that require both a high rate
of flow and a frequent change of flow, for example, switching between an off and on
position, or in the case of a three-way valve, switching between different flow paths.
SUMMARY
[003] The methods and devices disclosed herein overcome the above
disadvantages and improves the art by way of a valve arrangement that keeps flow
paths primed and ready for sudden switching between an off and on position while
accommodating a high rate of flow.
[004] A valve assembly comprises a valve body extending along a
longitudinal axis. The valve body comprises a first end portion and a second end
portion, and an inner compartment extending through the valve body from the
second end portion towards the first end portion. A first fluid port in to the valve body
is perpendicular to the longitudinal axis. A second fluid port in to the inner
compartment is spaced from the first fluid port, and the second fluid port is
perpendicular to the longitudinal axis. A third fluid port in to the inner compartment is
spaced from the second fluid port, and the third fluid port is perpendicular to the
longitudinal axis, and the second fluid port is between the third fluid port and the first
fluid port. A fourth fluid port is parallel to the longitudinal axis, and the fourth fluid
port fluidly connects the second end portion to the inner compartment. A spool is in
the inner compartment, and the spool is configured to selectively reciprocate in the
inner compartment between a first position adjoining the first end portion to a
second position adjoining the second end portion. The spool comprises a first fluid
receptacle configured to block fluid flow to the third fluid port and to fluidly
communicate with the second fluid port when the spool adjoins the first end portion.
The first fluid receptacle is configured to fluidly communicate with the second fluid
port and with the third fluid port when the spool adjoins the second end portion. A
second fluid receptacle is configured to receive fluid pressure from the fourth fluid
port and is configured to fluidly seal the fourth fluid port from the first fluid port.
[005] Additional objects and advantages will be set forth in part in the
description which follows, and in part will be obvious from the description, or may be
learned by practice of the disclosure. The objects and advantages will also be
realized and attained by means of the elements and combinations particularly
pointed out in the appended claims.
[006] It is to be understood that both the foregoing general description and
the following detailed description are exemplary and explanatory only and are not
restrictive of the claimed invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[007] Figure 1A is a cross-section view of a valve arrangement.
[008] Figure 1B is a cross-section view of an alternative valve arrangement.
[009] Figure 2 is a schematic fluid flow arrangement.
[01 0] Figures 3A-3E are cross-section views of a valve arrangement
comprising fluid flow paths.
DETAILED DESCRIPTION
[01 1] Reference will now be made to the examples which are illustrated in
the drawings. Wherever possible, the same reference numbers will be used
throughout the drawings to refer to the same or like parts. Directional references
such as "left" and "right" are for ease of reference to the figures, and are not to limit
the installation direction of the assembled valve arrangement.
[012] Figure 1A is a cross-section view of a valve arrangement. The valve
arrangement includes a valve body 1. The valve body extends along a longitudinal
axis A-A. A first fluid port 7 in to the valve body is perpendicular to the longitudinal
axis. A second fluid port 6 , or control port, in to the inner compartment is spaced
from the first fluid port, and the second fluid port 6 is perpendicular to the
longitudinal axis. A third fluid port 11 in to the inner compartment 14 is spaced from
the second fluid port 6 , and the third fluid port 11 is perpendicular to the longitudinal
axis A-A. The second fluid port 6 is between the third fluid port 11 and the first fluid
port 7 . A fourth fluid port 2 13 is parallel to the longitudinal axis A-A, and the fourth
fluid port 2 13 fluidly connects the second end portion 2 to the inner compartment 14.
[01 3] The valve body 1 and has a first end portion 2 and a second end
portion 3 . The arrangement includes a regulation valve 4 located at the first end
portion 2 and solenoid valve 5 located at the second end portion 3 . Supply fluid
under pressure can flow from a first fluid port 7 to the solenoid valve 5 via conduit
16. When the solenoid valve is energized, supply fluid flows from the first fluid port 7
to the solenoid valve 5 to a second end 10 of a spool 8 . The fluid moves the spool 8
toward the regulation valve 4 , thus, allowing the first fluid port 7 to fluidly
communicate with the second fluid port 6 . Fluid flowing from the second fluid port 6
can flow to a control component 80, for example, an engine brake or other device
that can receive fluid under pressure. When the solenoid valve 5 is energized, the
first end 9 of the spool 8 abuts the regulation valve 4 .
[014] While in the energized, or on position, fluid cannot flow from the
second fluid port 6 to the third fluid port 11 via the inner compartment 14. However,
fluid moves outside the valve 1, along the housing 25. O-rings 13 can seal fluid
pathways between the valve body 1 and housing 25, creating a pathway between
the second fluid port 6 and the third fluid port 11. When control pressure is
alleviated, the fluid pathway between the valve outer body 111 and housing 25
allows the fluid to flow to the first end 9 of the spool. This allows fluid to create
pressure against the first end 9 of the spool. A predetermined pressure can be
maintained by the regulation valve 4 . This can benefit the arrangement in several
ways, for example, it keeps the system primed and ready to transition from the first,
or off, position to the second, or on, position, when the solenoid valve 5 is not
energized. The pathway between the second fluid port 6 and the third fluid port 11
also prevents hydraulic lock from occurring during the transition from the on to the
off position. It further assists in moving the spool 8 toward the solenoid valve 5
along the axis A-A during the transition from the on position to the off position.
[01 5] When in the off position, the solenoid valve 5 is not energized and the
second end 10 of the spool is positioned against a portion of the valve body 1 closer
to the solenoid valve 5 toward the second end portion 3 of the valve body 1. The
solenoid valve 5 can be a three-way valve, allowing fluid to flow to the spool 8 when
on or to an exhaust or fluid reservoir when off. A metered leakage path, in the form
of an undercut 12 on the spool, forms opening 19 , which permits leakage from first
fluid port 7 towards second fluid port 6 . In the off position, fluid can also flow from
first fluid port 7 at the first end of the spool through opening 19. When a passthrough
30 in the spool communicates with second fluid port 6 , excess fluid
pressure can be relieved via pressure relief path 2 11 to a tank 50 attached to the
regulation check valve 4 , as by overcoming the spring force of spring 42 against the
check ball 4 1. The spring is biased against a plug 43 that can be have vents 47 or
tessellations for exhausting fluid to the tank 50. The arrangement in the off position
keeps the valve primed and ready for a transition from the off position to the on
position.
[016] When a high pressure is desired to the control component attached to
control port 6 , the solenoid is powered on. The first fluid port 7 at system (high)
pressure fluid, which is passed to conduit 16. The conduit 16 can be drilled in to the
valve body 1 and plugged by plug 35, as illustrated in Figure 1A. Or, the conduit 160
can be drilled in to the housing 25 as illustrated in Figure 1B. Other manufacturing
techniques, such as casting and molding can be used alone or together with the
drilling to form the housing 25 and its affiliated paths and conduits. The high
pressure fluid passes through a three way valve or solenoid and to the spool 8 . The
spool moves towards the first end portion 2 . A lip 20 on the spool moves to abut rim
45 of the regulation check valve 4 to block the release of pressure through the
check valve. This permits the increased control pressure to pass to second fluid port
6 without leaking out of regulation valve 4 . The pass-through 30 is also blocked by
the valve body 1.
[01 7] Figures 3A-3E are additional cross-section views of a valve
arrangement. The arrangements include an internal compartment 14 where the
spool 8 is located. The spool 8 has an arm 22 that connects the first end 9 of the
spool to the second end 10 of the spool. The first end 9 of the spool 8 includes a
first fluid receptacle 18 . The second end 10 of the spool 8 includes a second fluid
receptacle 17. Fluid can flow to the internal compartment 14 along first fluid pathway
100 through first fluid port 7 . Fluid can flow to the solenoid valve 5 (illustrated by
symbols as a three-way valve) along conduit 16. The solenoid can block fluid flow to
second fluid receptacle 17 , or pass fluid to a sump or exhaust 60, or pass fluid to
second fluid receptacle 17 to prime it for motion. Figure 3A illustrates that fluid can
enter internal compartment 14. Maintaining the fluid at a preset pressure can prime
the control component attached to port 6 and alternatively or additionally prime the
spool 8 for motion.
[01 8] When in the on or energized position, shown in Figure 3C, the
solenoid valve 5 allows fluid to flow along path 207 to the fourth fluid port and the
second fluid receptacle 17 , moving the spool 8 toward the regulation valve 4 . A
different pressure than the system or preset pressure, such as a higher control
pressure, can be supplied to the control port 6 to actuate the control component
along flow path 104. The high pressure also overcomes the spring force of spring 23
to move the spool 8 . The spring 23 fits in an inner recess 24 in the first fluid
receptacle 18.
[01 9] When in the off position, as shown in Figure 3B, the undercut 12
allows fluid to flow in the opening 19 from the first fluid port 7 to the second fluid port
6 along relief path 102A. Fluid can be bled off at the regulation valve 4 . Because the
lip 20 is away from the regulation valve 4 , fluid can pass between valve outer body
111 and housing 25 along second relief path 102B.
[020] But when in the fully on position, relief paths 102A & 102B are closed
because pass-through 30 is blocked by the valve body 1. And, lip 20 abuts
regulation valve rim 45, which blocks the flow path through third fluid port 11.
[021] When control component fluid pressure control is complete, the fluid
pressure supplied to the valve 1 can return from a higher control pressure to a lower
system or preset pressure. With high enough preset pressure at first fluid port 7 ,
fluid will not drain back through first fluid port 7 , and the valve will be primed for fast
return to the on position. Thus, it is beneficial to maintain a higher pressure at first
port 7 than at control port 6 . The metered leakage at opening 19 and metered flow
through pass-through 30 help accomplish the requisite pressure difference between
first port 7 and second port 6 .
[022] To relieve control pressure, Figure 3D shows a return path 106A. The
relieved control pressure can exhaust out regulation valve 4 following at least
second return path 106B, or by joining system pressure fluid from path 201 within
second fluid receptacle 18 . The preset or system pressure supplied to first fluid port
7 can be relieved through regulation valve 4 , as needed. Fluid from first fluid
receptacle 17 can be routed by 3-way valve 5 to a sump or exhaust 60 via third
return path 106C.
[023] When returning to the off position, the spool begins in the on position
but transitions to the off position along an intermediate pathway. Shown in Figure
3E, control fluid can flow along intermediate return path 108A from the second fluid
port 6 to the third fluid port 11 between the housing 25 and the valve body 1 with the
flow path sealed by o-rings 13 . When the spool 8 moves to an intermediate position,
lock-relief path 108B opens. This can create a pressure against the first end 9 of the
spool 8 because fluid fills the first fluid receptacle 18 . This pressure can assist the
spring 23 in moving the spool 8 toward the solenoid valve 5 when the solenoid valve
is de-energized. The lock-relief path 108B alleviates hydraulic lock, or a suctionbased
force retaining first fluid receptacle against the regulation valve 4 . The control
fluid can also move check ball 4 1 and exit regulation valve along intermediate relief
path 108C. Thus, the first fluid receptacle 18 is positioned with respect to the third
fluid port 11 and the second fluid port 6 such that, at a first intermediate spool
position, fluid flow in to the first fluid receptacle 18 is only through the third fluid port
11. But as the spool slides to the off position, a second intermediate position permits
fluid flow in to the first fluid receptacle 18 through both the third fluid port 11 and the
second fluid port 6 ; this flow path remains through the spool reaching the off
position.
[024] Once spool 8 moves from the intermediate position to the off position,
the alternative flow paths of Figure 3A become available at the three way valve or
solenoid, as designed. The relief paths 102A-102C of Figure 3B also return. The
metered leakage path or opening 19 , pass-through 30, and regulation valve 4 are
accessible to fluid pressure. Preset, or system pressure, fluid flow between the first
fluid port 7 to the second fluid port 6 keeps the arrangement primed and ready to
transition from the off to the on position.
[025] The valve arrangement can be inserted into a bore in housing 25
using o-rings 13 to seal the fluid. The valve arrangement can be held in place by a
retaining mechanism such as a retaining bolt or dowel pin. O-rings 13 can be used
to separate fluids, for example, supply fluid, control fluid, and exhaust fluid. The
fluids can be the same type of fluid (e.g. oil) but under different pressures in the
various compartments and ports (e.g. supply port, control port, or exhaust port).
[026] The valve arrangement works well in devices requiring a high flow rate
(thus high pressure) and a quick transition between the off and on position. The
arrangement can normally remain in the off position until energized. When in the off
position, fluid in second fluid receptacle 17 can flow out of the solenoid valve 5 to a
sump or exhaust 60. As a three-way valve, the solenoid valve 5 can direct flow to
the spool 8 when energized and to the exhaust 60 when de-energized.
[027] When in the off position, there can be regulation pressure due to the
check ball arrangement on the first end 9 of the spool 8 . In this position, the stepped
edge 2 1 on the exterior of the first receptacle of the spool can be higher on a first
side of the spool to overlap the control port 6 so that the majority of the flow area is
shut off. But on a second side of the exterior of the first receptacle of the spool,
undercut 12 is made so that a small opening 19 , or metered leakage path, exists
between the valve body 1 and the spool. The opening 19 allows a small amount of
flow into the control port. This flow can pass through the undercut 12 in the spool
and through a drilled port (the pass-through 30) in the spool to reach the chamber at
the end of the spool. A calibrated regulation valve 4 (e.g. check valve or ball valve)
can sit on the end of the valve body 1 and maintain a preset level of pressure in the
chamber at the end of the spool. This pressure keeps fluid (e.g. oil) moving through
the system to prevent aeration and to keep the downstream system primed for fast
response. The exiting fluid can be sent to tank 50. Should the assembly experience
a pressure in excess of the preset level of pressure, the check mechanism, such as
ball 4 1, moves against spring 42 to vent the excess. But when the lip 20 of the first
receptacle abuts the rim 45, flow through regulation valve 4 is blocked, and a control
pressure different from the preset pressure can pass through the valve body from
first fluid port 7 to the (control) second fluid port 6 .
[028] Figure 2 illustrates schematically the fluid flow paths possible as the
spool 8 in the valve body 1 selectively reciprocates in the inner compartment 14
between a first position (on position) adjoining the first end portion 2 to a second
position (off position) adjoining the second end portion 3 . A pump 70 draws fluid
from a sump 7 1 to control fluid pressure. The sump 7 1 is optionally joined to
exhaust path 205 or exhaust 60 via sump path 716. Pumped fluid travels path 200,
where it can enter first fluid port 7 via path 201 , or be directed via path 203 to
solenoid 5 . Path 203 can be within housing 25, or drilled in to valve body 1 as
conduit 16. Solenoid 5 comprises upper schematic half 52 indicating powered fluid
flow via power and control source 5 1, and lower schematic half 53 indicating
unpowered fluid flow with passive mechanism 54.
[029] When the solenoid is powered to pass fluid, fluid travels to fourth fluid
port 2 13 via path 207 in to valve body 1 to move spool 8 . Fluid can travel between
first port 7 to control path 209 attached to control port 6 and from there to control
device 80. As above, an pressure relief path 2 11 permits excess pressure relief to
tank 50 when the solenoid is off.
[030] When the valve arrangement is in the on position, hydraulic force
created from the pressurized fluid flowing from the solenoid valve 5 can overcome
the spring 23 bias on the spool 8 and move the spool toward the regulation valve 4
along axis A. The spool can comprise one or more diameter changes 15 in the
second end 10 . As the spool bangs against the inner compartment wall when
returning to the off position, the diameter change on the spool prevents burrs or
marring from interfering with spool action. The spool end can further comprise
notches in the circumference to allow the fluid pressure to act across the full spool
diameter. In the on position, the control port is open to the supply pressure so the
high-pressure fluid can flow to the control component (e.g. engine brake). Flow
between the regulation valve 4 and the first end 9 of the spool can be shut off.
However, when the spool moves, another port (e.g. third port 11) drilled through the
valve body 1 can allow flow between the regulation valve 4 and the first end 9
portion of the spool. This third port 11 allows fluid to travel into first fluid receptacle
18 while the spool 8 moves back to the off position. This bleed back of fluid in to first
fluid receptacle 18 prevents hydraulic lock and aids the spring 23 in moving the
spool 8 , thus, increasing the response time of the valve arrangement. The bleed
back fluid, when high pressure control fluid, can provide pressure to the third port 11
to assist spool movement to the off position.
[031] By implementing a fluid control strategy, the valve 1 is fluidly
controlled. Electrical assist is necessary to power the solenoid 5 and can be
necessary to power the alternative three way valve. By controlling the pressure
supplied to the first through fourth fluid ports, the spool is selectively reciprocated
within the inner compartment and a first fluid pathway to the second end of the
spool can be supplied or relieved, a second fluid pathway through the regulation
valve can permit bleed off of fluid pressure or be blocked, and the third fluid port can
be connected fluidly to the first fluid port or blocked. Appropriate computer control,
such as tangible memory device, processor executable instructions stored in the
memory device, and processor can implement methods of operating the valve in
accordance with the disclosed structures and paths.
[032] Other implementations will be apparent to those skilled in the art from
consideration of the specification and practice of the examples disclosed herein.

WHAT IS CLAIMED IS:
1. A valve arrangement comprising:
a valve body, the valve body comprising an axis, a first end portion, and a
second end portion;
a regulation valve located at the first end portion of the valve body;
a solenoid valve located at the second end portion of the valve body;
a first fluid port in the valve body;
a second fluid port in the valve body;
a third fluid port located in the valve body;
a spool located inside the valve body between the regulation valve and the
solenoid valve; and
an undercut in an exterior surface of the spool forming an opening between
the spool and the valve body,
wherein the spool moves axially along the axis of the valve body;
wherein the spool comprises a first end and a second end;
wherein the spool moves between a first position and a second position;
wherein the first end of the spool is located between the regulation check
valve and the solenoid valve along the axis;
wherein the second end of the spool is located between the first end of the
spool and the solenoid valve along the axis;
wherein the first end of the spool in the second position is nearer the
regulation check valve than the first end of the spool when in the first position;
wherein the third fluid port is in fluid communication with the second fluid
port;
wherein the third fluid port is in fluid communication with the first fluid port
through the second fluid port when the spool is in the second position;
wherein fluid flows from the second fluid port to the first end of the spool
through the third fluid port when the spool moves from the second position to the
first position;
wherein the first fluid port is in fluid communication with the second fluid port
when the spool is in the second position;
wherein the first fluid port is in fluid communication with the solenoid valve;
and
wherein fluid flows from the first fluid port to the first end portion of the spool
through the opening when the spool is in the first position.
2 . The valve arrangement of claim 1, wherein the second fluid port is in fluid
communication with an engine brake.
3 . The valve arrangement of claim 1, wherein the regulation valve is a check
valve.
4 . The valve arrangement of clam 1, wherein the regulation valve is a ball valve.
5 . The valve arrangement of claim 1, comprising a first o-ring and a second oring,
wherein fluid flows from the second fluid port to the third fluid port in between
the first o-ring and the second o-ring.
6 . The valve arrangement of claim 1, wherein fluid exits the solenoid valve
when the spool is in the first position.
7 . The valve arrangement of claim 1, wherein fluid exits the regulation valve
when the spool is in the first position.
8 . The valve arrangement of claim 1, wherein fluid flowing through the third fluid
port prevents hydraulic lock as the spool moves from the second position to the first
position.
9 . The valve arrangement of claim 1, wherein fluid flows through the third fluid
port to move the spool move toward the solenoid valve as the spool moves from the
second position to the first position.
10 . The valve arrangement of claim 1, wherein the regulation valve is configured
to maintain a pressure less than the pressure of the fluid flowing through the second
fluid port.
11. The valve arrangement of claim 1, wherein the first end of the spool abuts the
regulation valve when in the second position.
12 . The valve arrangement of claim 1, wherein fluid flow through the opening is
blocked when the spool is in the second position.
13 . The valve arrangement of claim 1, wherein the solenoid valve is a three-way
valve.
14. A valve comprising:
an axially extending valve body comprising:
a first end portion and a second end portion;
an inner compartment extending through the valve body from the second
end portion towards the first end portion;
a first fluid port in to the valve body;
a first fluid pathway connecting the second end portion to the inner
compartment;
a second fluid port in to the inner compartment, the second fluid port
spaced from the first fluid port;
a third fluid port in the inner compartment, the third fluid port spaced from
the second fluid port, and the second fluid port is between the third
fluid port and the first fluid port; and
a second fluid pathway connecting the first end portion to the inner
compartment;
a spool in the inner compartment, the spool configured to selectively
reciprocate in the inner compartment between a position adjoining the first
end portion to a position adjoining the second end portion, the spool
comprising:
a first fluid receptacle configured to receive fluid pressure from the first
fluid pathway and further configured to fluidly seal the first fluid
pathway from the first fluid port;
a second fluid receptacle connected to the first fluid receptacle, the
second fluid receptacle comprising:
a pass-through configured to fluidly communicate with the second fluid
port when the spool adjoins the second end portion, and to be
blocked by the valve body when the spool adjoins the first end
portion; and
a lip spaced from the pass-through, the lip configured to selectively
block the third fluid port when the spool adjoins the first end
portion.
15 . The valve of claim 14, further comprising a regulation valve in the second
end portion, wherein the lip selectively abuts the regulation valve to block fluid flow
to the third fluid port.
16. The valve of claim 14 or 15 , further comprising a solenoid valve configured to
selectively fluidly connect the first fluid pathway to the first fluid port.
17 . The valve of claim 15 wherein the second fluid receptacle comprises an outer
undercut, and when the spool is adjacent the second end portion, the undercut
fluidly connects the first port to the regulation valve through the pass-through.
18 . The valve of claim 14, wherein the first fluid receptacle is connected to the
second fluid receptacle by an arm.
19 . The valve of claim 14, wherein the second receptacle comprises an outer
undercut, and when the spool is adjacent the second end portion, the undercut
fluidly connects the third port to the first port through the second port.
20. The valve of claim 15 , further comprising a spring, wherein the second
receptacle comprises an inner recess, and wherein the spring is biased between the
inner recess and the regulation valve.
2 1. A valve assembly comprising:
a housing;
a valve body, the valve body comprising an axis, a first end portion, and a
second end portion;
a regulation valve located at the first end portion of the valve body;
a solenoid valve located at the second end portion of the valve body;
a first fluid port in the valve body;
a second fluid port in the valve body;
a spool located inside the valve body between the regulation valve and the
solenoid valve;
an undercut on an outer edge of the spool forming an opening between the
spool and the valve body;
a third fluid port located in the valve body; and
a fluid pathway between the housing and the valve body,
wherein the spool moves axially along the axis of the valve body between a
first position and a second position;
wherein the spool comprises a first end and a second end;
wherein the first end of the spool is located between the regulation check
valve and the solenoid valve along the axis;
wherein the second end of the spool is located between the first end of the
spool and the solenoid valve along the axis;
wherein the first end of the spool in the first position is nearer the regulation
check valve than the first end of the spool when in the second position;
wherein, when the spool is in the second position, the second fluid port fluidly
communicates with the third fluid port through the fluid pathway between the
valve body and the housing;
wherein the third fluid port is in fluid communication with the first fluid port
through the second fluid port when the spool is in the second position;
wherein, when the spool is in the second position, fluid flows from the second
fluid port to the first end of the spool through the third fluid port;
wherein the first fluid port is in fluid communication with the second fluid port
when the spool is in the first position;
wherein the first fluid port is in fluid communication with the solenoid valve;
and
wherein fluid flows from the first fluid port to the first end of the spool through
the opening when the spool is in the second position.
22. A valve assembly comprising:
a valve body extending along a longitudinal axis, the valve body comprising:
a first end portion and a second end portion;
an inner compartment extending through the valve body from the second
end portion towards the first end portion;
a first fluid port in to the valve body, the first fluid port perpendicular to the
longitudinal axis;
a second fluid port in to the inner compartment, the second fluid port
spaced from the first fluid port, the second fluid port perpendicular to
the longitudinal axis;
a third fluid port in to the inner compartment, the third fluid port spaced
from the second fluid port, the third fluid port perpendicular to the
longitudinal axis, and the second fluid port is between the third fluid
port and the first fluid port; and
a fourth fluid port parallel to the longitudinal axis, the fourth fluid port
fluidly connecting the second end portion to the inner compartment;
a spool in the inner compartment, the spool configured to selectively
reciprocate in the inner compartment between a first position adjoining the
first end portion to a second position adjoining the second end portion, the
spool comprising:
a first fluid receptacle, the first fluid receptacle configured to block fluid
flow to the third fluid port when the spool adjoins the first end portion,
and the first fluid receptacle is configured to fluidly communicate with
the second fluid port and with the third fluid port when the spool
adjoins the second end portion; and
a second fluid receptacle configured to receive fluid pressure from the
fourth fluid port and further configured to fluidly seal the fourth fluid
port from the first fluid port.
23. The valve assembly of claim 22, wherein the first fluid receptacle further
comprises:
a pass-through configured to selectively fluidly communicate with the
second fluid port; and
a lip spaced from the pass-through, the lip configured to selectively block
the third fluid port when the lip abuts a rim in the first end portion.
24. The valve assembly of claim 22, further comprising a regulation valve in the
first end portion, and the regulation valve comprises a rim, wherein the third fluid
port adjoins the regulation valve, and wherein the first fluid receptacle comprises a
lip that abuts the rim to block fluid flow through the third fluid port when the spool
adjoins the first end.
25. The valve assembly of claim 22 or claim 24, wherein the first fluid receptacle
further comprises an exterior stepped edge comprising an undercut, and the
undercut and the inner compartment selectively form a metered leakage path
between the first fluid port and the second fluid port.
26. The valve assembly of claim 22, wherein the second fluid receptacle further
comprises exterior notches facing the fourth fluid port.
27. The valve assembly of claim 22, wherein the second fluid receptacle further
comprises an exterior diameter change facing the fourth fluid port.
28. The valve assembly of any one of claims 22-24, wherein the first fluid
receptacle is positioned with respect to the third fluid port and the second fluid port
such that, at a first intermediate position, fluid flow in to the first fluid receptacle is
only through the third fluid port, but at a second intermediate position and at the
second position, fluid flow in to the first fluid receptacle is through both the third fluid
port and the second fluid port.