Patent Description:
The present invention relates to a tire inflation/deflation system, and more particularly to a wheel valve assembly for a tire inflation/deflation system.

A tire inflation/deflation system for a vehicle, such as a central tire inflation/deflation system (CTIS), provides the vehicle with the versatility of adjusting tire pressures while the vehicle is stationary or in motion. For example, the tire pressure of one or more wheel assemblies of the vehicle that are in fluid communication with the tire inflation/deflation system may be decreased to increase tire traction, or increased to reduce rolling resistance and increase the vehicle's fuel efficiency and tire life-span. In addition, tire inflation/deflation systems increase a vehicle's maneuverability over differing terrains and reduce maintenance requirements. Drivers of vehicles with a tire inflation/deflation system may directly control pressure in each tire to enhance mobility of the vehicle based on the terrain. Also, the tire inflation/deflation system may maintain a desired pressure to counteract leaks in each tire.

A tire inflation/deflation system, such as a CTIS, typically includes an air supply source in selective fluid communication with a tire via a pneumatic conduit. The pneumatic conduit may include a wheel valve with a pressure-side port for allowing the air supply source to provide pressurized air to the tire and alternatively for allowing the tire to deflate. Typically, the pressure-side port fluidly connects to only a single fluid flow line. The single fluid flow line carries airflow from the pressure source to the wheel valve and carries exhaust airflow from the tire via the pressure-side port of the wheel valve.

One problem with conventional wheel valves for tire inflation/deflation systems is that the reliable control of the wheel valve may be susceptible to environmental factors, such as changes in fluid pressure and/or contamination of the valve by debris or the like.

A central tire inflation/deflation system with a timed function CTIS wheel valve of the prior art is disclosed in <CIT>.

The present invention provides an improvement in the reliable control of a wheel valve assembly for a tire inflation/deflation system, such as for a CTIS.

The invention as defined in claim <NUM> provides a valve for a wheel valve assembly for a tire inflation/deflation system includes a fluid-operated damper that is configured to control the timing of a valve member of the wheel valve assembly, in which the wheel valve assembly further includes a vent passage fluidly connected to a fluid chamber of the damper and at least one vent valve that is configured to open or close the vent passage, such that when the vent valve is activated to open the vent passage, fluid in the damper chamber is permitted to escape, thereby maintaining a desired pressure level in the damper chamber.

By maintaining the desired pressure level in the damper fluid chamber, the reliable control of the valve member timing may be improved. Such features may be particularly advantageous when leakage of fluid (e.g., air) into the damper fluid chamber increases the pressure level therein, resulting in changes to the valve member timing. Allowing the excess fluid pressure within the damper chamber to escape via the exemplary vent feature thereby maintains the timing of the valve member within a suitable range according to the design parameters of the wheel valve assembly.

In exemplary embodiments, the vent valve is a resilient fluid pressure-energized valve element that is energized by fluid pressure within the system to enhance sealing performance when the valve element closes the vent passage. The resilient valve element may be activated to open the vent passage when a pressure differential on opposite sides of the resilient valve element reaches or exceeds a certain level.

In exemplary embodiments, the resilient fluid pressure-energized valve element is a lip seal, such as a U-cup seal.

The vent valve or multiple vent valves also may be suitably configured to reduce contamination internal to the wheel valve assembly. Such contamination may include dirt, oil, tire talc, sand, salt, water, snow, or other such contaminants exposed to the vehicle during use.

In exemplary embodiments, a multiple-redundant configuration of the vent valves may be employed to enhance the contamination mitigating effect. For example, the multiple vent valves may be configured to provide a suitable isolation gap between the vent valves which serves as an airlock-type feature for trapping contaminants.

The use of a damper with the exemplary wheel valve assembly can prevent immediate closure of the valve by dampening movement of the valve member to its closed position. Preventing immediate closure of the valve enables the valve to overcome one or more shortcomings of diaphragm-style valves.

The wheel valve according to an aspect of the present invention may be placed into existing tire inflation systems in place of existing valves, without modifying pneumatic lines of the existing inflation system. Thus, the exemplary valve may be operated by a single fluid flow line, receive pressure from the single fluid flow line, and exhaust to the single fluid flow line, for example.

According to an aspect, a valve for use in an inflation/deflation system, includes: a valve body having a first inlet/outlet port fluidly connectable to a second inlet/outlet port; a valve member movable within the valve body between a first position and a second position for fluidly connecting or disconnecting the first inlet/outlet port and the second inlet/outlet port; and a fluid-operated damper operably connected to the valve member to dampen movement of the valve member from the second position to the first position; wherein, when in a first state, the first inlet/outlet port is fluidly disconnected from the second inlet/outlet port by the valve member; wherein the valve is configured to transition to a second state when a fluid pressure at the first inlet/outlet port is at or above a prescribed pressure threshold, and when in the second state the first inlet/outlet port is fluidly disconnected from the second inlet/outlet port; wherein, when the valve is in the second state, lowering the fluid pressure below the prescribed pressure threshold causes the valve to transition from the second state to a third state; wherein, when in the third state, the first inlet/outlet port is fluidly connected to the second inlet/outlet port while the damper dampens movement of the valve member from the second position to the first position to maintain the valve in the third state for a prescribed period of time; wherein the damper includes a damper fluid chamber; and wherein the valve further includes a vent passage fluidly connected to the damper fluid chamber, and a vent valve configured to open and close the vent passage, such that when the vent passage is opened by the vent valve fluid is permitted to vent from the damper fluid chamber.

According to another aspect, a valve for use in an inflation/deflation system, includes: a valve body having a first inlet/outlet port fluidly connectable to a second inlet/outlet port; a valve member movable within the valve body between a first position and a second position for fluidly connecting or disconnecting the first inlet/outlet port and the second inlet/outlet port; and a fluid-operated damper operably connected to the valve member to dampen movement of the valve member from the second position to the first position; wherein, when in a first state, the first inlet/outlet port is fluidly disconnected from the second inlet/outlet port by the valve member; wherein the valve is configured to transition to a second state when a fluid pressure at the first inlet/outlet port is at or above a prescribed pressure threshold, and when in the second state the first inlet/outlet port is fluidly disconnected from the second inlet/outlet port; wherein, when the valve is in the second state, lowering the fluid pressure below the prescribed pressure threshold causes the valve to transition from the second state to a third state; wherein, when in the third state, the first inlet/outlet port is fluidly connected to the second inlet/outlet port while the damper dampens movement of the valve member from the second position to the first position to maintain the valve in the third state for a prescribed period of time; wherein the fluid-operated damper includes a body portion that at least partially forms a fluid timing chamber, and a timing piston movable in the timing chamber, the timing piston separating the timing chamber into a first portion and a second portion; and wherein the body portion includes a restrictive fluid passage for restricting fluid flow from the first portion of a timing chamber to the second portion of the timing chamber.

According to another aspect, a valve for use in an inflation/deflation system, includes: a valve body having a first inlet/outlet port fluidly connectable to a second inlet/outlet port; a valve member movable within the valve body between a first position and a second position for fluidly connecting or disconnecting the first inlet/outlet port and the second inlet/outlet port; and a fluid-operated damper operably connected to the valve member to dampen movement of the valve member from the second position to the first position; wherein, when in a first state, the first inlet/outlet port is fluidly disconnected from the second inlet/outlet port by the valve member; wherein the valve is configured to transition to a second state when a fluid pressure at the first inlet/outlet port is at or above a prescribed pressure threshold, and when in the second state the first inlet/outlet port is fluidly disconnected from the second inlet/outlet port; wherein, when the valve is in the second state, lowering the fluid pressure below the prescribed pressure threshold causes the valve to transition from the second state to a third state; wherein, when in the third state, the first inlet/outlet port is fluidly connected to the second inlet/outlet port while the damper dampens movement of the valve member from the second position to the first position to maintain the valve in the third state for a prescribed period of time; wherein the damper includes a damper fluid chamber, a timing piston movable in the damper fluid chamber, and a seal member disposed in a radial groove of the timing piston for abutting a surface forming at least a portion of the damper fluid chamber, wherein the seal member is movable within the radial groove of the timing piston to serve as a check valve, the check valve being configured to restrict fluid flow from a first portion of the timing chamber to a second portion of the timing chamber across the radial groove when the seal member engages a first axial face of the radial groove, and the check valve being configured to permit fluid flow from the second portion of the timing chamber to the first portion of the timing chamber across the radial groove when the seal member engages a second axial face of the radial groove; and wherein at least one of the first axial face and the second axial face includes a stepped surface for reducing surface area contact with the seal member.

According to another aspect, a central inflation/deflation system for a vehicle, includes: the valve according to any of the foregoing aspects or embodiments; a tire forming a fluid reservoir fluidly connected to the second inlet/outlet port of the valve; a fluid control system fluidly connected to the first inlet/outlet port of the valve; and a pressure source with an outlet fluidly connected to an inlet of the control system.

The following description and the annexed drawings set forth certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention as defined by the appended claims may be employed. Other objects, advantages and novel features according to aspects of the invention will become apparent from the following detailed description when considered in conjunction with the drawings.

The principles and aspects according to the present invention have particular application to a tire inflation/deflation system, such as a central tire inflation/deflation system (CTIS), and in particular to a wheel valve assembly for a CTIS that permits inflation and deflation of vehicle tires, and thus will be described below chiefly in this context. It is understood, however, that the principles and aspects disclosed herein may be applicable to other fluid systems where it is desirable to reduce or increase pressure of a fluid other than a CTIS, as would be understood by those having ordinary skill in the art.

Referring now in detail to the drawings, and initially to <FIG>, a portion of a vehicle with an exemplary tire inflation/deflation system <NUM> is illustrated schematically. In the illustrated embodiment, the tire inflation/deflation system <NUM> is a central tire inflation/deflation system (also referred to as CTIS <NUM> herein). As shown, the CTIS <NUM> generally includes a pressure source <NUM>, a control system <NUM>, a controller <NUM> that may control the pressure source <NUM> and the control system <NUM>, one or more exemplary wheel valves <NUM>, one or more fluid reservoirs, such as one or more vehicle tires <NUM>, and one or more fluid flow lines 22a - 22e. In the illustrated embodiment, the system <NUM> includes four tires <NUM> and four wheel valves <NUM> (also referred to as wheel valve assemblies, or simply valves), although the system <NUM> may include fewer or greater of such components.

In exemplary embodiments, the controller <NUM> may include a computer processor and a memory device to operate the pressure source <NUM> and the control system <NUM>. Operation of the pressure source <NUM> and the control system <NUM> allows the controller <NUM> to control fluid flow from the pressure source <NUM> to operate each valve <NUM>. Communication lines, illustrated as dashed lines, may operably connect the controller <NUM> to various components of the pressure source <NUM> and the control system <NUM> to allow operation of each valve <NUM>. For example, the communication lines may allow electrical impulses to be communicated. In an embodiment, the communication lines are able to carry electrical signals to and from the controller <NUM>. In another embodiment, the controller <NUM> may bidirectionally communicate with components of the vehicle, for example to determine a speed of the vehicle.

The controller <NUM> may operate the pressure source <NUM> and the control system <NUM> to control each valve <NUM> to be in a closed state, a charged state (also known as a "reset state" or an "initialized state"), or an open state. Each valve <NUM> may remain in the open state for a prescribed period of time to allow each corresponding vehicle tire <NUM> to be inflated or deflated.

The pressure source <NUM> may include a fluid pump <NUM>, such as a pneumatic compressor, a cooler <NUM>, an air dryer <NUM>, and a system reservoir <NUM>. The fluid pump <NUM> may include an intake port for receiving ambient fluid, such as ambient air, and may include an outlet fluidly connected to an inlet of the cooler <NUM>. The cooler <NUM> may include an outlet fluidly connected to an inlet of the air dryer <NUM>. The air dryer <NUM> may include an outlet fluidly connected to an inlet of the system reservoir <NUM>.

The controller <NUM> may initiate the fluid pump <NUM> to suction ambient fluid, such as ambient air. If the ambient fluid is a compressible fluid, the fluid pump <NUM> may pressurize the fluid as the fluid pump <NUM> provides the fluid to the system reservoir <NUM> via the cooler <NUM> and the air dryer <NUM>. For example, if the fluid pump <NUM> includes a compressor, the compressor may compress ambient air to provide pressurized air to the system reservoir <NUM> via the cooler <NUM> and the air dryer <NUM>.

The fluid pump <NUM> may discharge pressurized fluid out of the outlet of the fluid pump <NUM> to provide the pressurized fluid to the inlet of the cooler <NUM>. The cooler <NUM> may cool the pressurized fluid, which may cause the pressurized fluid to condense. For example, if the pressurized fluid is pressurized air, the pressurized air may condense which may cause the water in the pressurized air to condense.

The cooler <NUM> may discharge cooled pressurized air from the outlet of the cooler <NUM> to provide the cooled pressurized air to the inlet of the air dryer <NUM>. The air dryer <NUM> may remove water molecules from the rest of the cooled pressurized air to prevent water from building up in the system reservoir <NUM>, the control system <NUM>, each valve <NUM>, or each vehicle tire <NUM>.

The air dryer <NUM> may discharge dried pressurized air out of the outlet of the air dyer <NUM> to provide the dried pressurized air to the inlet of the system reservoir <NUM>. In an embodiment, the fluid pump <NUM> may provide fluid directly to the system reservoir <NUM>.

The system reservoir <NUM> may hold pressurized fluid until the controller <NUM> instructs the system reservoir <NUM> discharge the pressurized fluid from an outlet of the system reservoir <NUM> to provide the pressurized fluid to an inlet of the control system <NUM> for operating each valve <NUM> and/or for inflating the corresponding vehicle tire <NUM>. For example, the system reservoir <NUM> may hold pressurized air and discharge the pressurized air to the inlet of the control system <NUM>. In an embodiment, the fluid pump may provide fluid directly to the control system <NUM>.

The system reservoir <NUM> may provide pressurized fluid to each vehicle tire <NUM> via the fluid flow line 22a when the control system <NUM> fluidly connects the system reservoir <NUM> to each valve <NUM> and the valve <NUM> is open.

Each valve <NUM> may include a first inlet/outlet port <NUM> (also referred to as a control port) fluidly connected to an outlet of the control system <NUM>, which ultimately may be fluidly connected to ambient fluid (e.g., ambient air), as described above. Each valve <NUM> also may include a second inlet/outlet port <NUM> (also referred to as a tire port) fluidly connected to the corresponding vehicle tire <NUM> via a fluid flow line. In an embodiment, more than four valves are provided, for example, <NUM> or <NUM> valves may be provided. In another embodiment less than four valves are provided.

In the closed state, the valve <NUM> may be closed, thereby fluidly disconnecting the first inlet/outlet port <NUM> from the second inlet/outlet port <NUM>. In the charged state (as shown in <FIG>), the valve <NUM> may be closed. In the open state (as shown in <FIG>), the valve <NUM> may be open, thereby fluidly connecting the first inlet/outlet port <NUM> to the second inlet/outlet port <NUM>. As illustrated schematically, the valve <NUM> may remain in the open state for a prescribed period of time. While open, the valve <NUM> may allow the vehicle tire <NUM> to be inflated or to be deflated.

As shown in the illustrated embodiment, the valve <NUM> includes an exemplary vent feature <NUM>, which includes a vent passage <NUM> and one or more exemplary vent valves <NUM>. The vent passage <NUM> is fluidly connected to a fluid chamber of a damper <NUM> of the valve <NUM> (described in further detail below) to enable fluid to escape from the fluid chamber and thereby relieve pressure. In the illustrated embodiment, the vent feature <NUM> provides internal venting such that the vent passage <NUM> fluidly connects the fluid chamber of the damper <NUM> with the first/inlet outlet port <NUM>. As shown, one or more of the vent valves <NUM> may include a check valve that restricts fluid flow into the chamber of the damper <NUM>, and permits fluid flow out of the damper chamber at a certain pressure level, as discussed below particularly with reference to <FIG>.

As shown in the illustrated embodiment, the control system <NUM> may include one or more fluid flow lines 22c - 22e, one or more supply valves <NUM>, one or more external venting valves <NUM>, at least one supply pressure sensor <NUM>, and one or more inflation/deflation pressure sensors <NUM>. In the illustrated embodiment, the control system <NUM> includes four supply valves <NUM>, four external venting valves <NUM>, and four inflation/deflation pressure sensors <NUM> to correspond with the four tires <NUM>. In another embodiment, the fluid flow lines of the control system may form at least a portion of the fluid flow lines of the central tire inflation/deflation system that fluidly connect the control system to the pressure source and to each valve. In another embodiment, the fluid flow lines of the central tire inflation/deflation system-that connect the control system to the pressure source and to each valve-may form at least a portion of the fluid flow lines of the control system.

Each fluid flow line 22c - 22e may fluidly connect each supply valve <NUM> and each external venting valve <NUM> to at least one of the pressure source <NUM> or to the valve <NUM>. Each fluid flow line 22c may fluidly connect the inlet of the corresponding supply valve <NUM> to the outlet of the pressure source <NUM>. For example, each fluid flow line 22c may fluidly connect to the fluid flow line 22a.

Each fluid flow line 22d may fluidly connect the outlet of the corresponding supply valve <NUM> to the first inlet/outlet port <NUM> of the corresponding valve <NUM>. For example, each fluid flow line 22d may fluidly connect to the corresponding fluid flow line 22b. Fluidly connecting each supply valve <NUM> to the corresponding first inlet/outlet port <NUM> allows each supply valve <NUM> to provide pressurized fluid to the corresponding first inlet/outlet port <NUM> to control each valve <NUM>.

Controlling each valve <NUM> to open allows the pressure source <NUM> to provide pressurized fluid through the fluid flow line 22a to the control system <NUM> to each fluid flow line 22b and to the vehicle tire <NUM>. The pressurized fluid may flow into each valve <NUM> through the corresponding first inlet/outlet port <NUM> and flow out of each valve <NUM> through the corresponding second inlet/outlet port <NUM> to allow the pressurized fluid to flow into each vehicle tire <NUM>, which may cause inflation of each vehicle tire <NUM>.

Controlling each valve <NUM> to open also allows each vehicle tire <NUM> to provide pressurized fluid through the corresponding fluid flow line 22b to the control system <NUM> where the pressurized fluid may be expelled through the corresponding external venting valve <NUM>. The pressurized fluid may flow into each valve <NUM> through the corresponding second inlet/outlet port <NUM>, through the corresponding first inlet/outlet port <NUM>, through the corresponding fluid flow line 22b, and through the corresponding fluid flow line 22e. From the corresponding fluid flow line 22e, the pressurized fluid may flow to the corresponding external venting valve <NUM> and may be exhausted by the corresponding external venting valve <NUM> (such as to external atmosphere), which may cause deflation of the vehicle tire <NUM>.

Each fluid flow line 22e may fluidly connect the corresponding external venting valve <NUM> to each corresponding valve <NUM>. For example, each fluid flow line 22e may fluidly connect to the corresponding fluid flow line 22d to fluidly connect to the outlet of the corresponding external venting valve <NUM>.

Each supply valve <NUM> may be in communication with the controller <NUM> and fluidly connected to the first inlet/outlet port <NUM> of the corresponding valve <NUM> via the corresponding fluid flow lines 22b, 22d. When the system reservoir <NUM> holds pressurized fluid the pressurized fluid may be provided to the first inlet/outlet port <NUM> when the corresponding supply valve <NUM> is open. Providing pressurized fluid to each first inlet/outlet port <NUM> allows the corresponding vehicle tire <NUM> to inflate when the valve <NUM> is in the open state. In an embodiment, more than four supply valves are provided. In another embodiment less than four supply valves are provided.

Each external venting valve <NUM> may be in communication with the controller <NUM> and fluidly connected with the first inlet/outlet port <NUM> of the corresponding valve <NUM> via the corresponding fluid flow lines 22b, 22d, 22e. The controller <NUM> may open each external venting valve <NUM> independently to fluidly connect the corresponding first inlet/outlet port <NUM> with ambient air. Connecting each first inlet/outlet port <NUM> with ambient air allows the corresponding vehicle tire <NUM> to deflate to ambient air when the corresponding valve <NUM> is in the open state. In an embodiment, more than four vent valves are provided. In another embodiment less than four vent valves are provided.

The supply pressure sensor <NUM> may be operably connected to each fluid flow line 22c, which may fluidly connect the outlet of the pressure source <NUM> and the inlet of each supply valve <NUM>. The supply pressure sensor <NUM> may be in communication with the controller <NUM> to provide the controller <NUM> with a reading of the pressure of the pressurized fluid provided by the pressure source <NUM>.

Each inflation/deflation pressure sensor <NUM> may be operably connected to the corresponding fluid flow line 22d, which may fluidly connect the corresponding first inlet/outlet port <NUM> with the corresponding supply valve <NUM> and the corresponding external venting valve <NUM>. The inflation/deflation pressure sensor <NUM> may be in communication with the controller <NUM> to provide the controller <NUM> with a reading of the pressure of fluid flowing between each supply valve <NUM> and the corresponding valve <NUM>. In an embodiment, more than four inflation/deflation pressure sensors are provided. In another embodiment less than four inflation/deflation pressure sensors are provided.

When the controller opens each supply valve <NUM> and closes the corresponding external venting valve <NUM>, the pressurized fluid from the pressure source <NUM> may flow to the corresponding valve <NUM>. Each supply pressure sensor <NUM> and the corresponding inflation/deflation pressure sensor <NUM> may provide the pressure readings to the controller <NUM>. The pressure reading of each inflation/deflation pressure sensor <NUM> may rise to a level equal to the pressure reading of the corresponding supply pressure sensor <NUM>. By way of non-limiting example, when each valve <NUM> is open and the corresponding vehicle tire <NUM> is inflated to <NUM> pounds per square inch gage (psig), the pressure reading of the corresponding pressure sensor <NUM> and the corresponding inflation/deflation pressure sensor <NUM> may be <NUM> psig.

Alternatively, by way of non-limiting example, when each valve <NUM> is closed and the corresponding vehicle tire <NUM> is inflated to <NUM> psig, the pressure reading of the corresponding pressure sensor <NUM> and the corresponding inflation/deflation pressure sensor <NUM> may be <NUM> psig. If a predetermined pressure level of each vehicle tire <NUM> is <NUM> psig, for example, the corresponding valve <NUM> should be opened to allow each vehicle tire <NUM> to be inflated to <NUM> psig.

The controller <NUM> may be configured to determine whether the valve <NUM> should be opened and to determine whether the vehicle tire <NUM> should be inflated or deflated. For example, the controller <NUM> may have an input for a user to select the predetermined pressure level for each vehicle tire <NUM>. The controller <NUM> may operate the pressure source <NUM> and the control system <NUM> to inflate or deflate each vehicle tire <NUM> to reach the selected predetermined pressure level.

To facilitate inflation and deflation of the vehicle tires <NUM>, the controller <NUM> may determine the current state of the valves <NUM>. For example, the controller <NUM> may determine whether each valve <NUM> is in the closed state, charged state, or the open state based on a history of pressurized fluid provided to the valve <NUM> at the direction of the controller <NUM>. The controller <NUM> may store the history in the memory device.

The history stored may include the pressure level of pressurized fluid provided by the pressure source <NUM>, the pressure level of pressurized fluid provided by each supply valve <NUM>, and a time history of each pressure level. The history stored may also include a timeline of operation of the pressure source <NUM>, the supply valve <NUM>, and the external venting valve <NUM>.

For example, each valve <NUM> may be configured to have a charge pressure threshold at the corresponding first inlet/outlet port <NUM> that is greater than an opening pressure threshold at the first inlet/outlet port <NUM>. The charge pressure (also known as a "reset pressure" or "initialization pressure") threshold may be greater than the vehicle tire <NUM> pressure to counter the vehicle tire <NUM> pressure. The charge pressure may counter any biasing force that biases the valve <NUM> in the closed state.

Each valve <NUM> may be configured to transition from the closed state to the charged state in a prescribed charge time period. By way of non-limiting example, the prescribed charge time period may be <NUM> seconds or less when pressurized fluid is provided to the first inlet/outlet port <NUM>. The valve <NUM> may also be configured to transition from the charged state to the open state in a prescribed period of time. By way of non-limiting example, the valve <NUM> may be configured to transition from the charged state to the open state in <NUM> seconds or less once pressure begins to lower at the first inlet/outlet port <NUM>.

The valve <NUM> may be configured to transition from the open state to the closed state in a prescribed period of time open. By way of non-limiting example, the prescribed period of time open may be <NUM> seconds. In an embodiment, the prescribed period of time open is less than <NUM> seconds. In another embodiment, the prescribed period of time open is greater than <NUM> seconds.

The memory device of the controller <NUM> may include the configurations of each valve <NUM> and maintain a record of each in action made by the pressure source <NUM> or the control system <NUM>. In an embodiment, the opening pressure threshold at each first inlet/outlet port may be greater than a maximum desired pressure level of fluid within the vehicle tire. The maximum desired pressure level may be a maximum manufacturer recommended pressure rating of the vehicle tire.

When charging (resetting/initializing) each valve <NUM>, the controller <NUM> may keep a record of providing the pressurized fluid at or above the charge pressure threshold to the corresponding first inlet/outlet port <NUM> of each valve <NUM> for <NUM> seconds or longer. The controller <NUM> may determine that each valve <NUM> is in the charged position based on the known pressure provided to each first inlet/outlet port <NUM> for the prescribed period of time.

When opening the valve <NUM>, the controller <NUM> may keep a record of lowering the pressure level of the pressurized fluid below the opening pressure threshold at each first inlet/outlet port <NUM> to allow the corresponding valve <NUM> to transition from the charged state to the open state. The controller <NUM> may adjust the fluid flow from the pressure source <NUM> to adjust the pressure of the pressurized fluid to a pressure below the opening pressure threshold to transition the valve <NUM> into the open state. The controller <NUM> may adjust and/or maintain the fluid flow from the pressure source <NUM> to maintain the pressure of the pressurized fluid at a pressure below the opening pressure threshold to prevent the valve <NUM> from transitioning to the charged state from the open state.

The controller <NUM> may determine that each valve <NUM> is in the open state based on the known pressure at the corresponding inflation/deflation pressure sensor <NUM> and an amount of time elapsed since pressure level lowered below the opening pressure threshold. Once opened, each valve <NUM> may close after the prescribed period of time open. The controller <NUM> may determine whether each valve <NUM> has closed based on the amount of time elapsed since opening each valve <NUM> and the pressure values provided by the corresponding inflation/deflation pressure sensor <NUM> over time.

The controller <NUM> may determine the pressure level of the fluid within the vehicle tire <NUM> based on the pressure values provided by the supply pressure sensor <NUM> and the inflation/deflation pressure sensor <NUM> over time in relation to the states of the pressure source <NUM>, the supply valve <NUM>, and the external venting valve <NUM> over time.

Once the pressure level within the vehicle tire <NUM> is determined, the controller <NUM> may determine whether the valve <NUM> should be re-opened to either inflate or deflate the vehicle tire <NUM> based on a comparison of the selected pressure level for the vehicle tire <NUM> compared to the pressure level of the vehicle tire <NUM> determined by the controller <NUM>.

If the determined pressure level is below the selected pressure level, the controller <NUM> may open the valve <NUM>, the system reservoir <NUM>, and the supply valve <NUM> to inflate the vehicle tire <NUM>. While the valve <NUM> is in the open state, the controller <NUM> may adjust and/or maintain the fluid flow from the pressure source <NUM> to maintain the pressure of the pressurized fluid at a pressure below the opening pressure threshold and above the determined pressure of fluid within the vehicle tire <NUM> to inflate the vehicle tire <NUM>.

If the determined pressure level is above the selected pressure level, the controller <NUM> may open the valve <NUM> and the corresponding external venting valve <NUM> to deflate the corresponding vehicle tire <NUM>. While the valve <NUM> is in the open state, the controller <NUM> may adjust and/or maintain the fluid flow from the pressure source <NUM> to maintain the pressure of the pressurized fluid at a pressure below the opening pressure threshold and below the determined pressure of fluid within the vehicle tire <NUM> to deflate the vehicle tire <NUM>. The controller <NUM> may keep the valve <NUM> open or re-open the valve <NUM> until the pressure of the fluid inside the vehicle tire <NUM> reaches the selected pressure level. In an embodiment, the controller may keep the keep the valve open or re-open the valve until the pressure of the fluid inside the vehicle tire reaches ambient air pressure.

Fluid pressure levels may vary inside one of the vehicle tires <NUM> and at the corresponding inflation/deflation pressure sensor <NUM> as the corresponding valve <NUM> is repeatedly re-opened to deflate air inside the vehicle tire <NUM>. A spike of pressure above the charge pressure threshold may occur each time the valve <NUM> is charged (reset/initialized) and a following drop in pressure may indicate the valve <NUM> is open. By way of non-limiting example, after about <NUM> second a spike of pressure may charge (reset/initialized) the valve <NUM>. By way of non-limiting example, after about <NUM> seconds, the pressure may drop to allow the valve <NUM> to open.

The air pressure within the vehicle tire <NUM> may drop as the air within the vehicle tire <NUM> vents from the vehicle tire <NUM>. By way of non-limiting example, the air pressure measured by the inflation/deflation pressure sensor <NUM> may gradually drop with a reference pressure of <NUM> psig as the valve <NUM> transitions from the opened state to the closed state.

As the vehicle tire <NUM> deflates, the pressure of the air within the vehicle tire <NUM> and the pressure of the air measured by the inflation/deflation pressure sensor <NUM>-while the valve <NUM> is open-may reduce each subsequent reopening of the valve <NUM>.

The pressure measured by the inflation/deflation sensor <NUM> may correlate with the air pressure within the vehicle tire <NUM>. Thus, a pressure sensor is not needed within the vehicle tire <NUM> to determine pressure of the air within the vehicle tire <NUM>.

When the vehicle tire <NUM> is being inflated, the inflation/deflation sensor <NUM> would measure the same initial spike of air pressure. After lowering the air pressure to the opening pressure threshold, the air pressure measured by the inflation/deflation sensor <NUM> would increase at an increasing rate as valve <NUM> closes, until after the prescribed period of time open when the inflation/deflation sensor <NUM> reaches the pressure of the pressurized air provided by the pressure source <NUM> (<FIG>). As the vehicle tire <NUM> is inflated the pressure within the vehicle tire <NUM> may gradually increase at a decreasing rate as the valve <NUM> closes.

Turning to <FIG>, a portion of a wheel assembly <NUM> may include a wheel <NUM>, one of the vehicle tires <NUM>, and the exemplary wheel valve assembly <NUM> assembled into the wheel <NUM>. As shown, the wheel valve assembly <NUM> may be placed at a radially outward portion of the wheel <NUM> that is off-set from a wheel axis (not shown) that the wheel <NUM> rotates about. In an embodiment, the valve <NUM> is placed at another location of the wheel <NUM>.

Referring to <FIG> outer views of the exemplary wheel valve <NUM> are shown. As shown, the wheel valve <NUM> generally includes a valve body <NUM>, which may define the first inlet/outlet port <NUM> and define a second inlet/outlet port <NUM>. The valve body <NUM> may be partially formed by two separate housing bodies 120a, 120b that sealingly connect to one another to form an outer housing of the valve body <NUM>. The second inlet/outlet port <NUM> and the first inlet/outlet port <NUM> may be formed in the housing body 120b. As shown, the first inlet/outlet port <NUM> may be cylindrical for receiving a male connector (not shown) of a fluid flow line leading to the control system <NUM>. The second inlet/outlet port <NUM> may be fluidly connected to the vehicle tire <NUM>. The second inlet/outlet port <NUM> may be cylindrical for receiving a male connector (not shown) of a fluid flow line leading to the vehicle tire <NUM>.

Referring to <FIG>, a cross-sectional view of the exemplary wheel valve assembly <NUM> is shown. As shown, the wheel valve assembly <NUM> includes a valve member <NUM>, a fluid-operated damper <NUM> operably connected to the valve member <NUM>, a timing resilient member <NUM>, a charge member <NUM> moveable within a primary chamber <NUM> formed by the valve body <NUM>, and a charge resilient member <NUM> for biasing the charge member <NUM>.

The charge member <NUM> (also referred to as a reset member or initialization member) may include a charge piston <NUM>. The charge piston <NUM> may have a radially outer profile perpendicular to a longitudinal axis <NUM> that is the same as a radially inner profile of an inner surface <NUM> of the valve body <NUM> to allow the charge piston <NUM> to move axially along the inner surface <NUM> within the primary chamber <NUM>. The charge piston <NUM> may be cylindrical and may have a circular radially outer profile that matches the radially inner profile of the inner surface <NUM>.

The charge piston <NUM> may include a radially outwardly facing groove that secures a sealing member <NUM>, such as a suitable seal, for example a resilient X-ring seal. The sealing member <NUM> may seal against the charge piston <NUM> and the inner surface <NUM> to prevent fluid flow between the inner surface <NUM> and the piston <NUM> when the piston <NUM> is stationary or moving.

The charge piston <NUM> may include a flow passage <NUM> for allowing fluid to flow between the first inlet/outlet port <NUM> and the second inlet/outlet port <NUM>. In the illustrated embodiment, the charge piston <NUM> is formed with a generally cup shape and the flow passage <NUM> extends through a bottom center portion of the charge piston <NUM>.

As shown, the charge piston <NUM> includes a valve seat portion <NUM> that sealingly engages with a sealing surface <NUM>, such as a suitable seal, at an axial end of the valve member <NUM> to fluidly disconnect the first inlet/outlet port <NUM> from the second inlet/outlet port <NUM>.

The charge piston <NUM> is axially moveable within the primary chamber <NUM> (also referred to as the control chamber) to move between its initial position (as shown in <FIG>) and its charged position (as shown in <FIG>). As shown in the illustrated embodiment, the charge piston <NUM> may be axially disposed in a first (e.g., lower) portion of the primary chamber <NUM> when the charge piston <NUM> is in the initial position. As shown in <FIG>, the wheel valve <NUM> is in a closed state when the charge piston <NUM> is in its initial position within the first (e.g., lower) portion of the primary chamber <NUM> while the valve member <NUM> is in its closed position abutting the charge piston <NUM> within the primary chamber <NUM>. The charge piston <NUM> is moveable to the charged position (<FIG>) and back to its initial position in the first portion of the primary chamber <NUM>. As shown in the comparison between <FIG> and <FIG>, the initial position of the charge piston <NUM> may correspond with both the closed state (<FIG>) and open state (<FIG>) of the wheel valve <NUM>.

The charge resilient member <NUM> biases the charge member <NUM> toward its initial position in the first (e.g., lower) portion of the primary chamber <NUM>. Biasing the charge member <NUM> allows the charge piston <NUM> to quickly return to its initial position from the charged position when the pressurized fluid provided to the first inlet/outlet port <NUM> is at or below the opening pressure threshold. The charge resilient member <NUM> may bias the charge piston <NUM> in a first axial direction extending from the second (e.g., upper) portion of the primary chamber <NUM> to the first (e.g., lower) portion of the primary chamber <NUM>. In the illustrated embodiment, the charge resilient member <NUM> extends from an axially intermediate portion <NUM> of the valve body <NUM> to an axially facing surface of the charge piston <NUM>. The charge resilient member <NUM> may be any type of resilient member or biasing member. For example, the charge resilient member <NUM> may be a spring, such as a coil spring, for example a metal coil spring.

Referring briefly to <FIG>, with continued reference to <FIG> for comparison, the charge piston <NUM> may be axially disposed in the second (e.g., upper) portion of the primary chamber <NUM> when the charge piston <NUM> is in its charged position. The second (e.g., upper) portion of the primary chamber <NUM> may be formed at an axially opposite end of the primary chamber <NUM> as the first (e.g., lower) portion of the primary chamber. When the valve member <NUM> is in its closed position sealingly engaging the charge piston <NUM>, the charge piston <NUM> moves the valve member <NUM> to the second portion of the primary chamber <NUM> when the charge piston <NUM> moves from its initial position to the charged position. Providing pressurized fluid at or above the charge pressure threshold may cause the charge piston <NUM> to move from the initial position to the charged position. While moving, the charge piston <NUM> moves the valve member <NUM> to place the valve <NUM> in the charged state.

The valve member <NUM> is disposed within a fluid flow path of the valve body <NUM> for fluidly connecting or disconnecting the first inlet/outlet port <NUM> and the second inlet/outlet port <NUM>. The valve member <NUM> is in a closed position fluidly disconnecting the flow path between the first inlet/outlet port <NUM> and second inlet/outlet port <NUM> when the valve member <NUM> is sealingly engaged with the charge piston <NUM> to close the flow passage <NUM> (as shown in <FIG> and <FIG>, for example). The valve member <NUM> is in an open position fluidly connecting the flow path between the first inlet/outlet port <NUM> and second inlet/outlet port <NUM> when the valve member <NUM> is disengaged and suitable spaced from the valve seat <NUM> to open the flow passage <NUM> (as shown in <FIG>, for example).

The valve body <NUM>, such as the valve body portion 120b, may include any suitable flow passages for fluidly connecting the first (e.g., control) inlet/outlet port <NUM> with the second (e.g. tire) inlet/outlet port <NUM>. For example, in the illustrated embodiment, the valve body <NUM> includes a radial passage <NUM> fluidly connecting the second inlet/outlet port <NUM> with an upper portion of the primary (e.g., control) chamber <NUM>, and also includes an axial passage <NUM> fluidly connecting the first inlet/outlet port <NUM> with a lower portion of the primary chamber <NUM>. The radial passage <NUM> may be axially offset from the axial passage <NUM> to prevent fluid flow from the first inlet/outlet port <NUM> to the second inlet/outlet port <NUM> when the charge piston <NUM> is in the charged position.

The damper <NUM> is configured to dampen movement of the valve member <NUM> from its open position (<FIG>) to the closed position (<FIG>). Dampening movement of the valve member <NUM> from the open position to the closed position allows the valve <NUM> to remain in the open state for the prescribed period of time open.

In the illustrated embodiment, the damper <NUM> is a fluid-operated damper including a timing fluid chamber <NUM> and a timing piston <NUM> moveable within the timing chamber <NUM>. In exemplary embodiments, the damper <NUM> also includes a check valve <NUM> for creating a pressure differential within the timing chamber <NUM>, and a restrictive flow passage <NUM> for delaying pressure equalization within the timing chamber <NUM>, as described in further detail below.

As shown, the timing chamber <NUM> may be formed by a sleeve <NUM> disposed within the intermediate portion <NUM> that circumscribes the central axis <NUM>. The timing chamber <NUM> may be filled with a fluid, such as air. The timing chamber <NUM> generally is sealed to contain a prescribed amount of the fluid in the chamber for reliable operation and timing of the valve <NUM>. As discussed in further detail below with exemplary reference to <FIG>, a vent feature <NUM> is provided to allow fluid to escape from the timing chamber <NUM>, such as in those circumstances when leakage in the valve allows additional fluid in excess of the prescribed amount to accumulate in the timing chamber <NUM>.

In exemplary embodiments, the timing piston <NUM> is moveable by a charge force from an initial position at a first (e.g., lower) portion of the timing chamber <NUM> (as shown in <FIG>, for example) to a charged position at a second (e.g., upper) portion of the timing chamber <NUM> (as shown in <FIG> or <FIG>, for example). The timing piston <NUM> may have a radially outer profile perpendicular to the central axis <NUM> that is the same as a radially inner profile of the sleeve <NUM> of the intermediate portion <NUM> to allow the timing piston <NUM> to move axially along the inner surface of the sleeve <NUM> within the timing chamber <NUM>. The timing piston <NUM> may be cylindrical and may have a circular radially outer profile that matches the radially inner profile of the inner surface of the sleeve <NUM>.

The axially intermediate portion <NUM> may be fixed to or formed as part of the housing <NUM>, such as the housing bodies 120a, 120b to form an upper end of the primary chamber <NUM>. For example, the axially intermediate portion <NUM> may have suitable threads to threadingly attach to suitable threads of the housing bodies 120a, 120b. The valve <NUM> may include seals <NUM>, <NUM> to restrict fluid leakage out of the valve <NUM>. Each seal <NUM>, <NUM> may be any suitable seal, such as an elastomeric O-ring.

The check valve <NUM> may be disposed within the timing piston <NUM> to prevent fluid flow from the first (e.g., lower) portion of the timing chamber <NUM> to the second (e.g., upper) portion of the timing chamber <NUM>, and to allow fluid flow from the second portion of the timing chamber <NUM> to the first portion of the timing chamber <NUM>. The exemplary check valve <NUM> and its operation are described in further detail below with exemplary reference to <FIG>.

The timing piston <NUM> is moveable from its charged position (<FIG> or <FIG>) toward its initial position (<FIG>) with a closing force that allows the valve member <NUM> to close. The closing force may be greater than the charge force. For example, the closing force may be based on the fluid resistance against the timing piston <NUM> as the timing piston <NUM> moves from the charged position to the initial position. The fluid resistance may be much greater when moving the timing piston <NUM> from the charged position to the initial position compared to the reverse, because fluid pressure may slowly equalize throughout the timing chamber <NUM> as the timing piston <NUM> moves.

The charge force may be based on fluid resistance against the timing piston <NUM> as the timing piston <NUM> moves from the initial position to the charged position. The fluid resistance may be negligible when moving the timing piston <NUM> to the charged position compared to the reverse. The fluid pressure may equalize throughout the timing chamber <NUM> more quickly as the timing piston <NUM> moves to the charged position compared to moving to the initial position.

The timing resilient member <NUM> may bias the valve member <NUM>, the timing piston <NUM>, and the charge piston <NUM> in the first axial direction to bias the valve <NUM> in the closed state. The timing resilient member <NUM> may be any type of resilient member or biasing member. For example, the timing resilient member <NUM> may be a spring, such as a coil spring, for example a metal coil spring. In the illustrated embodiment, the timing resilient member <NUM> is disposed within the timing chamber to circumscribe the axis <NUM> and engages an inner surface of the valve body portion 120a and an upper portion of the timing piston <NUM>.

The timing resilient member <NUM> may move the timing piston <NUM> from the charged position (<FIG> or <FIG>) to the initial position (<FIG>). When moving the timing piston <NUM> from the charged position to the initial position fluid may be forced through the restrictive flow passage <NUM> until the timing piston <NUM> approaches the first portion of the timing chamber <NUM>. The restrictive flow passage <NUM> may restrict fluid flow from the first (e.g., lower) portion of the timing chamber <NUM> to the second (e.g., upper) portion of the timing chamber <NUM> to delay pressure equalization between the first portion and the second portion.

In exemplary embodiments, the restrictive flow passage <NUM> is formed as a helical passage <NUM>. In the illustrated embodiment, the helical passage <NUM> spirals about the longitudinal axis <NUM> in an axial direction parallel to the longitudinal axis <NUM>. As shown, the helical passage <NUM> may be formed between a radially outer surface of the sleeve <NUM> and a radially inner surface of the intermediate portion <NUM>. For example, the helical passage <NUM> may be formed with a helical groove in the radially outer surface of the sleeve <NUM>. Such a helical groove provides a relatively simple and inexpensive way to provide the restrictive flow passage <NUM>. As shown, the restrictive flow passage <NUM> may be fluidly connected to the timing chamber <NUM> via a radial flow passage <NUM>, which may be formed at an end of or through the sleeve <NUM>.

In exemplary embodiments, the valve <NUM> may include a quick close port <NUM> to reduce a fluid pressure differential between the first (e.g., lower) portion and the second (e.g., upper) portion of the timing chamber <NUM> as the timing piston <NUM> reaches an end of its stroke while moving from the charged position (<FIG> or <FIG>) to the initial position (<FIG>). The quick close port <NUM> may fluidly connect the first portion to the second portion of the timing chamber <NUM>. For example, the quick close port <NUM> may allow fluid to flow in an axial direction from the first portion of the timing chamber to the second portion of the timing chamber.

In the illustrated embodiment, for example, the quick close port <NUM> includes a radially outwardly recessed portion (also referred to with reference number <NUM>) in the inner surface of the sleeve <NUM>. As shown, the recessed portion <NUM> extends in an axial direction along only a portion of the inner surface of the sleeve <NUM>. The recessed portion <NUM> may extend in the axial direction from the lower axial end of the sleeve <NUM> to allow fluid to flow through the recessed portion <NUM> past the timing piston <NUM> as the timing piston <NUM> is anywhere from <NUM>% to <NUM>% away from the end of its stroke as it travels upward. For example, the axial length of the recessed portion <NUM> may be configured to allow fluid to flow through the radially outwardly recessed portion <NUM> past the timing piston <NUM> when the timing piston <NUM> has reached an axial position that would indicate <NUM>% of time remaining for the timing piston <NUM> to reach the end of its stroke without the quick close port <NUM>. As shown, when the timing piston <NUM> moves from the charged position (<FIG> or <FIG>) to the initial position (<FIG>), a radially outward portion of the sealing member <NUM> disengages from the inner surface of the sleeve <NUM> at the radially outwardly recessed portion <NUM> to allow fluid to flow through the radially outwardly recessed portion <NUM>. Allowing fluid flow quickens pressure equalization between the first portion and the second portion of the timing chamber <NUM> to reduce resistance to movement of the timing piston in the first axial direction.

Referring particularly to <FIG>, the wheel valve <NUM> is illustrated in the exemplary charged state where the charge piston <NUM> has moved into its charged position and has moved the valve member <NUM> upwardly along with the charge piston <NUM>. Providing fluid with a fluid pressure at or above the charge pressure threshold at the first inlet/outlet port <NUM> may transition the valve member <NUM> and the charge piston <NUM> into their respective illustrated positions. In the illustrated state, the valve member <NUM> is still closing the flow passage <NUM> by providing sealing engagement of the sealing surface <NUM> with the valve seat <NUM>.

The valve member <NUM> may include a poppet <NUM> and the sealing surface <NUM> at an axial end of the poppet <NUM> for sealing against the charge piston <NUM>. In an embodiment, the valve member is another type of valve, for example a sliding valve. As shown, the valve member <NUM> may include a valve stem portion <NUM> (or tube) forming a body that extends axially along the central axis <NUM>. In the illustrated embodiment, valve stem portion <NUM> is fixed within a timing stem portion <NUM> (or tube) forming a longitudinally extending body that is operably coupled to the timing piston <NUM>. The valve stem portion <NUM> may be fixed for common axial movement with the timing stem portion <NUM> via a suitable thread or other any other fastener. In exemplary embodiments, the head of the poppet <NUM> is unitary with the valve stem portion <NUM> and/or the timing piston <NUM> is unitary with the timing stem portion <NUM>. Alternatively or additionally, the timing stem portion <NUM> may be unitary with the valve stem portion <NUM>.

As shown in the illustrated embodiment, the timing stem portion <NUM> and valve stem portion <NUM> are axially movable through a central through-hole in the intermediate portion <NUM>, such that movement of the respective stem portions <NUM>, <NUM> enables the timing piston <NUM> and the head of poppet <NUM> to move axially together. To maintain suitable sealing between the primary (e.g., control) chamber <NUM> and the timing chamber <NUM>, a seal <NUM> is provided in a seal groove of the intermediate portion <NUM> to engage with the radially outer surface of the timing stem portion <NUM> that extends through the through-hole in the intermediate portion <NUM>. The seal <NUM> may be any suitable seal, such as an X-ring seal, for example.

In exemplary embodiments, the timing stem portion <NUM> includes an internal axial flow passage <NUM> that is fluidly connected to an internal axial flow passage <NUM> of the valve stem portion <NUM>. As shown, the respective internal axial flow passages <NUM>, <NUM> fluidly connect a variable volume chamber <NUM> (shown best in <FIG>) with the primary chamber <NUM> which may be in fluid communication with the first (e.g., control) inlet/outlet port <NUM>. The variable volume chamber <NUM> may have a minimum volume when the valve member <NUM> is in the charged position (as shown in <FIG>), and may have a maximum volume that is larger than the minimum volume when the valve member <NUM> is in its initial position (as shown in <FIG>). Fluid contained within the variable chamber <NUM> may flow through the internal axial flow passages <NUM> and <NUM> to the primary chamber <NUM> to prevent fluid pressure build-up that may resist opening of the valve member <NUM>. As shown, the variable volume chamber <NUM> may be fluidly disconnected from the timing chamber <NUM> by a seal <NUM> that engages with an upper portion of the timing stem portion <NUM>. The seal <NUM> may be any suitable seal, such as an X-ring seal.

As mentioned above, the seal <NUM> at an axial end portion of the valve member <NUM> is configured to sealingly engage with the valve seat portion <NUM> of the charge piston <NUM> to seal against the charge piston <NUM> and prevent fluid flow therebetween. Preventing fluid flow between the charge piston <NUM> and the seal <NUM> may fluidly disconnect the first inlet/outlet port <NUM> and the second inlet/outlet port <NUM>. For example, the fluid flow from the first inlet/outlet port <NUM> through the primary chamber <NUM> to either second inlet/outlet port <NUM> may be prevented.

Turning to <FIG>, the wheel valve <NUM> is illustrated in the exemplary open state. When the valve <NUM> is in the charged state (<FIG>), reducing the fluid pressure at or below the opening pressure threshold at the first inlet/outlet port <NUM> may transition the valve <NUM> toward the open state. When the valve <NUM> is in the open state, the seal <NUM> may be axially spaced from the charge piston <NUM> to allow fluid to flow between the poppet <NUM> and the charge piston <NUM> via passage <NUM>. The poppet <NUM> may be in an open position and the charge piston <NUM> may be in an open position to allow fluid to flow from the first inlet/outlet port <NUM> to each second inlet/outlet port <NUM>.

The timing piston <NUM> is configured to dampen movement of the valve member <NUM> (e.g., poppet <NUM>) from the open position (<FIG>) to the closed position (<FIG>). For example, the timing resilient member <NUM> may bias the poppet <NUM> to close while the fluid in the first (e.g., lower) portion of the timing chamber <NUM> increases in pressure relative to the fluid in the second (e.g., upper) portion of the timing chamber <NUM>. The fluid in the first portion may force the check valve <NUM> to prevent fluid flow. The increased pressure of the fluid in the first (e.g., lower) portion of chamber <NUM> may cause the sealing member <NUM> to seal against the inner surface of the sleeve <NUM> to prevent fluid flow therebetween. Fluid from the first (e.g., lower) portion of the timing chamber <NUM> may only be able to equalize pressure with the fluid in the second (e.g., upper) portion of the timing chamber <NUM> by flowing through the restrictive flow passage <NUM> until the timing piston <NUM> reaches the quick close port <NUM>. Restricting the fluid flow may delay closure of the poppet <NUM> to allow fluid to flow through the primary chamber <NUM> between the first inlet/outlet port <NUM> and each second inlet/outlet port <NUM>.

The delayed closure may allow the poppet <NUM> to remain axially spaced from the charge piston <NUM> for the prescribed period of time open. By way of example and not limitation, the prescribed period of time open may be anywhere from <NUM>-<NUM> seconds, more particularly <NUM>-<NUM> seconds, and more particularly <NUM> seconds. In an embodiment, the prescribed period of time open may be based on a size of the vehicle tire, a desired pressure of the vehicle tire, and desired deflation rates of the vehicle tire.

Pressure at the second inlet/outlet port <NUM> may be reduced below the opening pressure threshold. For example, the pressure provided to the first inlet/outlet port <NUM> may be lowered, or completely removed, and the poppet <NUM> may remain axially spaced apart from the charge piston <NUM> for the prescribed period of time open. While the poppet <NUM> is axially spaced from the charge piston <NUM>, fluid may flow from the second inlet/outlet port <NUM> to the first inlet/outlet port <NUM>.

The fluid pressure at the second inlet/outlet port <NUM> may reduce toward ambient pressure by expelling fluid from the second inlet/outlet port <NUM> to the first inlet/outlet port <NUM>. For example, the first inlet/outlet port <NUM> may be fluidly connected to ambient air, such as when the corresponding external venting valve <NUM> (<FIG>) is open.

The poppet <NUM> may remain axially spaced from the charge piston <NUM> during the prescribed period of time open when the pressure at the first inlet/outlet port <NUM> is equal to ambient pressure. The fluid pressure at the second inlet/outlet port <NUM> may be reduced to ambient pressure when the first inlet/outlet port <NUM> is at ambient pressure and the valve <NUM> is opened. For example, ambient pressure may be <NUM> psig and the poppet <NUM> may remain axially spaced from the charge piston <NUM> for the prescribed period of time open.

When the damper <NUM> times out and moves to its end stroke position at the first (e.g., lower) portion of the timing chamber <NUM>, the poppet <NUM> moves axially corresponding with movement of the timing piston <NUM> to seal against the charge piston <NUM> via seal <NUM>, thereby closing the valve (as shown in <FIG>).

Referring to <FIG>, the exemplary check valve <NUM> between the first (e.g., lower) portion of the timing chamber <NUM> and the second (e.g., upper) portion of the timing chamber <NUM> will now be described in further detail. As briefly described above, the check valve <NUM> may be disposed within the timing piston <NUM> to prevent fluid flow from the first (e.g., lower) portion of the timing chamber <NUM> to the second (e.g., upper) portion of the timing chamber <NUM>, and to allow fluid flow from the second portion of the timing chamber <NUM> to the first portion of the timing chamber <NUM>. In the illustrated embodiment, the check valve <NUM> includes a sealing member <NUM> and one or more fluid passages <NUM>. The sealing member <NUM> may be disposed in a radially outward facing groove <NUM> of the timing piston <NUM> for abutting the inner surface of the sleeve <NUM> of the axially intermediate portion <NUM>. Fluid flow through each fluid passage <NUM> may be prevented when the sealing member <NUM> is engaged with the inner surface of the sleeve <NUM> and the timing piston <NUM>. For example, the sealing member <NUM> may be any suitable seal, such as an O-ring seal <NUM>, and the O-ring seal <NUM> may engage with the inner surface of the sleeve <NUM>. The O-ring seal <NUM> may shift within the groove <NUM> to engage with axial facing surfaces of the timing piston <NUM> when the timing piston <NUM> moves between its charged position (<FIG>) and its initial position (<FIG>), as discussed below.

The one or more fluid passages <NUM> may be any suitable passage or combination of passages for permitting or restricting fluid flow between the first (e.g., lower) and second (e.g. upper) portion of the timing chamber <NUM>. For example, at least a portion of the fluid passage <NUM> may extend to a radially outward facing surface of the timing piston <NUM> to allow the sealing member <NUM> to recede radially inwardly into each fluid passage <NUM>. In an embodiment, the fluid passage <NUM> may extend axially through the timing piston <NUM> and the sealing member may seal the fluid passage when the timing piston moves in the first axial direction.

As shown in <FIG>, when the valve <NUM> is in the exemplary closed state (corresponding with <FIG>), the sealing member <NUM> is centered in the groove <NUM> of the timing piston <NUM> such that a fluid seal is not made between the first (e.g., lower) and second (e.g., upper) portion of the timing chamber <NUM>. As such, fluid exchange is permitted between the volumes above and below the timing piston <NUM>.

As shown in <FIG>, when the valve <NUM> is moved from its closed state (corresponding with <FIG>) to its charged state (corresponding with <FIG>), the timing piston <NUM> moves upwardly in the timing chamber <NUM>. The seal member <NUM> is then shifted toward the bottom of the groove <NUM> to sealingly engage with a lower axially facing surface <NUM> of the groove <NUM>. The position of the seal member <NUM> is such that the flow passage <NUM> remains open to fluid flow from the second (e.g., upper) portion of the timing chamber <NUM> to the first (e.g., lower) portion of the timing chamber <NUM>.

As shown in <FIG>, when the valve <NUM> is moved from its charged state (e.g., corresponding with <FIG>) back to its initial state where the valve is closed (corresponding to <FIG>), the timing piston <NUM> moves downwardly in the timing chamber <NUM>. The seal member <NUM> is then shifted toward the top of the groove <NUM> to sealingly engage with an upper axially facing surface <NUM> of the groove <NUM>. The position of the seal member <NUM> is such that the flow passage <NUM> is closed to fluid flow from the first (e.g., lower) portion of the timing chamber <NUM> to the second (e.g., upper) portion of the timing chamber <NUM>. As described above, when moving the timing piston <NUM> from the charged position to the initial position fluid is forced through the restrictive flow passage <NUM> until the timing piston <NUM> approaches the first (e.g., lower) portion of the timing chamber <NUM>. The restrictive flow passage <NUM> may restrict fluid flow from the first (e.g., lower) portion of the timing chamber <NUM> to the second (e.g., upper) portion of the timing chamber <NUM> to delay pressure equalization between the first portion and the second portion.

In exemplary embodiments, the axial face <NUM> of the groove <NUM> includes a stepped surface, including axially offset stepped portion 170b. The stepped portion 170b minimizes the contact area of the sealing member <NUM> to minimize friction forces and sticking of the seal member <NUM> at the lower portion of the groove <NUM>. This enables the seal member <NUM> to move more freely in the groove <NUM>.

Referring now particularly to <FIG>, the exemplary vent feature <NUM> of the wheel valve assembly <NUM> will now be described in further detail.

Generally, to maintain the desired timing of the valve <NUM> via the damper <NUM>, the fluid (e.g., air) within the timing chamber <NUM> is sealed therein to maintain a suitable pressure level range. One issue that can occur with the wheel valve assembly <NUM> over the course of its life, however, is that leakage of fluid (e.g., air) may find its way into the timing chamber <NUM>, which can impact the reliable timing and control of the valve <NUM>. For example, the dynamic seals <NUM> and/or <NUM> may permit fluid from the primary chamber <NUM> and/or variable volume chamber <NUM> to leak into the timing chamber <NUM>. Other avenues of leakage into the timing chamber <NUM> include those from another pressurized source, such as pressure applied to the control line through seal <NUM>, for example. By way of non-limiting example, leakage of such fluid into the timing chamber <NUM> resulting in an increased pressure of 60psi may result in the timing of the damper <NUM> being <NUM> seconds longer than desired. Other factors also may affect the pressure level in the timing chamber, such as variations in temperature, pressure, or inherent manufacturing issues.

As shown in the illustrated embodiment, the exemplary vent feature <NUM> provides a vent passage <NUM> fluidly connected to the timing chamber <NUM> and at least one vent valve <NUM> that is configured to open or close the vent passage <NUM>. When the vent valve <NUM> is activated to open the vent passage, fluid in the timing chamber <NUM> is permitted to escape, thereby maintaining the desired pressure level in the timing chamber <NUM>. Allowing the excess fluid pressure within the timing chamber <NUM> to escape via the exemplary vent feature <NUM> thereby maintains the timing of the valve member <NUM> within a suitable range according to the design parameters of the wheel valve assembly <NUM>.

The vent passage <NUM> may include any suitable passage or combination of passages that permits venting of excess fluid or excess fluid pressure from the timing chamber <NUM>. In exemplary embodiments, the vent feature <NUM> provides internal venting to fluidly connect the timing chamber <NUM> back to the primary (e.g., control) chamber <NUM> which is fluidly connected to the first (e.g., control) inlet/outlet port <NUM>. For example, the timing chamber <NUM> may be fluidly connected with the primary chamber <NUM> via the internal axial flow passage <NUM> extending through the valve stem portion <NUM> of the valve member <NUM>. It is understood, however, that other suitable flow paths for the vent passage(s) may be provided, which may extend through other suitable components or be ported to other fluid channels, as would be understood by those having ordinary skill in the art.

With exemplary reference to the fluid flow lines, F, shown in the illustrated embodiment, the vent passage <NUM> may include a first vent passage portion 63a that extends radially through an upper portion of the timing stem portion <NUM>. The first vent passage portion 63a may open through a radially outer side of the timing stem portion <NUM> into the timing chamber <NUM> above the timing piston <NUM> to fluidly connect with the second (e.g., upper) portion of the timing chamber <NUM>. The first vent passage portion 63a also may open through the opposite radially inward side of the timing stem portion <NUM> into a gap <NUM> between the timing stem portion <NUM> and the valve stem portion <NUM>.

The gap <NUM> forms an axial (second) vent passage portion 63b. As shown, the gap <NUM> between the timing stem portion <NUM> and valve stem portion <NUM> may widen at an axially intermediate widened gap portion 210a to permit insertion of the at least one valve member <NUM> in the fluid flow path of the vent passage <NUM>.

In the illustrate embodiment, a third vent passage portion 63c extends radially through the valve stem portion <NUM> to fluidly connect the second (axial) vent passage portion 63b with the axial internal passage <NUM> of the valve stem portion <NUM>. The axial internal flow passage <NUM> forms a fourth vent passage portion 63d that is fluidly connected to the primary chamber <NUM> via an opening <NUM> through the head portion of the valve member <NUM>, which permits fluid to flow to the first inlet/outlet port <NUM>.

As shown, one or more suitable seals <NUM>, <NUM>, such as O-ring seals, may be provided to seal the gap <NUM> (e.g., second vent passage portion 63b) between the timing stem portion <NUM> and valve stem portion <NUM> to urge the fluid through the flow path described above.

The at least one vent valve <NUM> may be any suitable valve or combination of valves provided at any suitable location(s) in the flow path of the vent passage <NUM> to permit or restrict fluid flow out of the timing chamber <NUM>.

In the illustrated embodiment, for example, the at least one vent valve <NUM> is disposed in the second (axial) vent passage portion 63b formed by the gap <NUM> between the valve stem portion <NUM> and timing stem portion <NUM>, such as in the widened gap portion <NUM>0b. As shown, the vent valve <NUM> is located at an axial position that is between the axially offset first (radial) vent passage portion 63a and third (radial) vent passage portion 63c to permit or restrict flow between these passages 63a, 63b.

In exemplary embodiments, the at least one vent valve <NUM> includes at least one check valve (also referred to with reference numeral <NUM>) that is configured to activate to open in response to a pressure differential acting on its opposite upstream and downstream sides <NUM>, <NUM>. For example, when the system is at rest with no or reduced pressure in the primary chamber <NUM> of the valve <NUM> (e.g., no or reduced pressure at the first inlet/outlet port <NUM>), a pressure differential is created between the timing chamber <NUM> and the primary chamber <NUM>. In the illustrated embodiment, this pressure differential is communicated via the first (radial) vent passage portion 63a fluidly connected to the timing chamber <NUM> and the third (radial) vent passage portion 63c fluidly connected to the primary chamber <NUM>. This pressure differential is communicated to the at least one valve member <NUM> via the gap <NUM> (e.g., second flow passage 63b), and acts on the opposite upstream and downstream sides <NUM>, <NUM> of the check valve <NUM>. The check valve <NUM> is activated to open the flow path when the pressure on its upstream side <NUM> (e.g., timing chamber pressure) is greater than the pressure on its downstream side <NUM> (e.g., primary chamber pressure). The pressure differential for activating the check valve <NUM> to open may be set to a specified level based on the configuration of the valve, as understood by those having ordinary skill in the art. In the illustrated embodiment, the check valve <NUM> is a one-way check valve that permits fluid flow only out of the timing chamber <NUM>.

The check valve functionality of the at least one vent valve <NUM> may be provided by any suitable check valve assembly or check valve element(s) (collectively referred to herein simply as the check valve <NUM>). For example, the exemplary check valve <NUM> may include a resilient lip seal, such as a U-cup seal, a duck-bill seal, or the like; a spring-loaded check valve, such as a spring-loaded ball assembly; or other suitable forms of check valve (e.g. one-way check valve), as would be understood by those having ordinary skill in the art. The exemplary check valve <NUM> may consist of only a single check valve element, such as with an exemplary lip seal, or may include a plurality of components, such as with a spring-loaded check valve.

In exemplary embodiments, the at least one vent valve (e.g., check valve) is formed by a fluid pressure-energized valve element <NUM> that is made with a resilient material (also referred to herein as a resilient fluid pressure-energized valve element, or fluid-energized valve element). Unlike a spring-loaded ball check valve which primarily is energized by spring force, the resilient fluid-energized valve element primarily is energized in response to fluid pressure acting on the valve element. Such a resilient fluid-energized valve element can therefore provide a relatively simplified construction and may improve the reliability of the valve <NUM>. Also due to the scale of the particular application, many ball-and-spring or poppet check valve designs may have a smaller sealing surface area which may make them more susceptible to contamination-based leakage.

In exemplary embodiments, the resilient fluid-energized valve element <NUM> may be a resilient seal having one or more lips which act to sealingly engage against one or more surfaces when fluid pressure is exerted on a first side of the seal that is greater than the opposite second side, and which act to disengage and unseal from the one or more surfaces when fluid pressure on the second side is greater than the first side. The resilient fluid-energized valve element <NUM> may be specifically configured to activate to open when the fluid pressure differential is greater than a prescribed amount.

The exemplary fluid-energized valve element <NUM> may be with any suitable resilient material or combination of materials. For example, the resilient material may be selected from a suitable polymeric material, such as nitrile, silicone, polyurethane, neoprene, ethylene-propylene, or combinations thereof; or may include other materials, such as filler materials.

In the illustrated embodiment, the vent valve <NUM> is a single component in the form of a U-cup seal <NUM> made with a resilient material. In the illustrated embodiment, the resilient material is urethane, such as polyurethane, for example. The U-cup seal <NUM> is in the form of a ring and includes two radially spaced apart lip portions <NUM> that project axially from a bridging portion, or base <NUM>. As shown, the U-cup seal <NUM> is located in the widened gap portion 210b between the valve stem portion <NUM> and timing stem portion <NUM> (e.g., second (axial) vent passage portion 63b) and is oriented with its base <NUM> toward the upstream first (radial) vent passage 63a, and with its lips <NUM> toward the downstream third (radial) vent passage 63c. The U-cup seal <NUM> may be held in place within the widened gap portion 210b by a retaining ring <NUM>, or any other suitable holder, such as groove or shoulder of a component of the valve <NUM>, for example.

An exemplary operation of the U-cup seal <NUM> as a check valve element will now be described. When fluid pressure exerted against the downstream side of the lips <NUM> of the U-cup seal <NUM> (communicated from the primary chamber <NUM>) is greater than the fluid pressure exerted against the upstream side of the lips <NUM> (communicated from timing chamber <NUM>), the lips <NUM> will be urged away from each other to enhance sealing against the corresponding sealing surfaces of the valve stem portion <NUM> and timing stem portion <NUM>, thereby preventing flow from the primary chamber <NUM> to the timing chamber <NUM>. On the other hand, when fluid pressure exerted against the upstream side of the lips <NUM> (communicated from the timing chamber <NUM>) is greater than the fluid pressure exerted against the downstream side of the lips <NUM> (communicated from the primary chamber <NUM>), the lips will be urged toward each other to disengage and unseal from the corresponding sealing surfaces of the valve stem portion <NUM> and timing stem portion <NUM>, thereby opening the flow path from the timing chamber <NUM> to the primary chamber <NUM>. By way of non-limiting example, the U-cup seal <NUM> (e.g., check valve <NUM>) may be configured to activate to open (e.g., unseal the lips) when the pressure on the upstream side (communicated from the timing chamber <NUM>) is about <NUM> psi or greater than the downstream side (communicated from the primary chamber <NUM>).

One possible effect of providing the vent feature <NUM> in the wheel valve assembly <NUM> is that contaminants, such as dirt, sand, salt, water, snow, or other such contaminants ingested into the flow path of the tire inflation/deflation system <NUM>, could migrate to the timing chamber <NUM> by bypassing the vent valve <NUM>. To mitigate such contamination, exemplary embodiments of the wheel valve assembly <NUM> provide a multiple-redundant configuration of vent valves, such as two or more vent valves <NUM>. The multiple vent valves may be configured to provide a suitable isolation gap between the vent valves which serves as an airlock-type feature for trapping contaminants.

In the illustrated embodiment, for example, the vent valve <NUM> is a first vent valve, and the vent feature <NUM> further includes a second vent valve 65b that is spaced apart from the first vent valve <NUM> in the fluid passage 63b to form an isolation gap <NUM> therebetween. In exemplary embodiments, the first vent valve <NUM> and the second vent valve 65b may have the same configuration, or the configurations may be different to provide different activation pressures for the valves <NUM>, 65b.

In the illustrated embodiment, both vent valves <NUM>, 65b are formed as U-cup seals having one-way check valve functionality, as described above. When fluid pressure from the timing chamber <NUM> is greater than fluid pressure in the isolation gap <NUM> by a specified amount, the first vent valve <NUM> (e.g., U-cup check valve) will be activated to open and vent into the isolation gap <NUM>. When fluid pressure in the isolation gap <NUM> is greater than fluid pressure from the primary chamber <NUM> by a specified amount, the second vent valve 65b (e.g., U-cup check valve) will be activated to open to vent from the isolation gap <NUM> to the primary chamber <NUM>.

Turning to <FIG>, another example of a wheel valve assembly <NUM> for a tire inflation/deflation system, such as a CTIS is shown, which is not covered by the claims, but useful for understanding the invention. The wheel valve assembly <NUM> may be utilized in the CTIS <NUM>, as shown and described in connection with <FIG>, by replacing the wheel valve assembly <NUM>; or the wheel valve assembly <NUM> may be used in a different tire inflation/deflation system.

Referring particularly to <FIG>, the wheel valve assembly <NUM> includes a valve body <NUM>. The valve body <NUM> may be substantially cylindrical in geometry. A tire port <NUM> is disposed toward the bottom of the valve body <NUM>. The tire port <NUM> may be in selective fluid communication with a tire (e.g., tire <NUM>) and a control unit (e.g., control <NUM>), as shown in <FIG> for example.

At least one control chamber <NUM> that is fluidly connected to one or more control ports (hidden from view) also are formed in the valve body <NUM>. The control ports are in fluid communication with the control unit <NUM> and the control chamber <NUM>. The control ports are in selective fluid communication with the tire port <NUM> via the control chamber <NUM> and a diaphragm <NUM> (described in further detail below).

In the illustrated example, the wheel valve assembly <NUM> includes a valve cover <NUM>. The valve cover <NUM> is coupled with the valve body <NUM> via suitable fasteners (not shown). As shown, the valve cover <NUM> forms an internal cover chamber <NUM>. The cover chamber <NUM> and the control chamber <NUM> are separated by, and partially defined by, the diaphragm <NUM>. As shown, the valve cover <NUM> at least partially contains a biasing member <NUM> and a backing plate <NUM>.

In the example, the diaphragm <NUM> includes a substantially discoid member including a first portion 326a and a second portion 326b. The first portion 326a is coupled between the cover <NUM> and valve body <NUM> such that the second portion 326b of the diaphragm <NUM> may actuate in an axial direction. The second portion 326b includes a first axially extending protrusion 327a. The first protrusion 327a defines a surface which selectively sealingly engages a protruding portion <NUM> of the valve body <NUM>. The second portion 326b also includes a second axially extending protrusion 327b which projects opposite the first protrusion 327a. The second protrusion 327b is engaged with, and at least partially located within, a complimentary depression in the lower surface of the backing plate <NUM>. The backing plate <NUM> includes a substantially cylindrical wall <NUM>, which may guide the backing plate <NUM> during actuation of the diaphragm <NUM>.

At a static state, the biasing member <NUM> engages an interior surface of the valve cover <NUM> at a first end, and engages a surface of the backing plate <NUM> at a second end. The backing plate <NUM> engages the diaphragm <NUM> and via the biasing member <NUM> drives the diaphragm <NUM> into sealing contact with the protruding portion <NUM>. The diaphragm <NUM> thereby seals a tire port channel <NUM>.

During inflation, deflation, or pressure checks of the tire, pressurized fluid enters the control chamber <NUM> via the control port(s) (hidden from view). The increased pressure in the control chamber <NUM> exerts a force on the diaphragm <NUM> in the axial direction and thereby at least partially compresses the biasing member <NUM>.

When the wheel valve assembly <NUM> is exposed to high temperatures during a static state, pressure may increase in the cover chamber <NUM>. The increased pressure in the cover chamber <NUM> may degrade the overall performance of the wheel valve assembly <NUM>. For example, the increased pressure in the cover chamber <NUM> may increase the axial force sealing the diaphragm <NUM> against the tire port <NUM> protruding portion <NUM>. The necessary pressure in the control chamber <NUM> to disengage the diaphragm <NUM> from the protruding portion <NUM> may then be increased.

Referring particularly to <FIG>, and also back to <FIG>, in order to overcome increased pressure in the cover chamber <NUM>, the wheel valve assembly <NUM> includes an exemplary vent valve <NUM>.

As shown, the vent valve <NUM> may include a first fluid passage <NUM>, which may be defined by the valve cover <NUM>, and a second fluid passage <NUM>, which may be defined by the valve body <NUM>. The first fluid passage <NUM> may extend radially through the valve cover <NUM>, and the second fluid passage <NUM> may extend radially through the valve body <NUM>. As shown, the first and second fluid passage <NUM>, <NUM> may be in fluid communication with each other via a third (axial) fluid passage <NUM>.

As shown, the vent valve <NUM> includes one or more resilient fluid pressure-energized valve elements <NUM> that are interposed between the first and second fluid passages <NUM>, <NUM>. The one or more resilient fluid pressure-energized valve elements <NUM> serve as one or more check valve elements that are configured to permit fluid flow in one direction through the third fluid passage <NUM>, and are configured to restrict fluid flow in an opposite direction through the fluid passage <NUM>.

Any suitable resilient fluid pressure-energized valve element <NUM> may be utilized to provide the desired check valve functionality. For example, the resilient fluid pressure-energized valve element <NUM> may be a resilient lip seal, such as a U-cup seal, a duck-bill seal, or the like. Unlike a spring-loaded ball check valve which primarily is energized by spring force, the resilient fluid pressure-energized valve element <NUM> primarily is energized in response to fluid pressure acting on the valve element. The exemplary resilient fluid pressure-energized valve element <NUM> may consist of only a single component, thereby simplifying construction and reliable performance when compared to a spring-loaded ball check valve assembly.

In the illustrated example, each resilient fluid pressure-energized valve element <NUM> is a single component in the form of a U-cup seal <NUM> made with a resilient material. The configuration of the U-cup seal <NUM> and operation thereof may be substantially similar or the same as that of the U-cup seal <NUM> described above in connection with the wheel valve assembly <NUM>. Also as shown in the illustrated embodiment, to mitigate contamination of the valve <NUM>, a multiple-redundant configuration resilient fluid pressure-energized valve elements <NUM> is provided, which also may be substantially the same as or similar to the redundant configuration described in connection with the wheel valve assembly <NUM>.

In the example, the resilient fluid pressure-energized valve element(s) <NUM> (e.g., U-cup seals) are mounted on a plug <NUM> that is inserted into the flow path between the first (radial) fluid passage <NUM> and the second (radial) fluid passage <NUM>, such as within a widened portion <NUM>, or cavity, of the third (axial) fluid passage <NUM>. The resilient fluid pressure-energized valve element(s) <NUM> (e.g., U-cup seals) may be held on the plug <NUM> via retaining ring(s) <NUM> or other suitable holding structure(s).

For examples where a single resilient fluid pressure-energized valve element <NUM> (e.g., U-cup seal) is utilized, when the pressure in the cover chamber <NUM> reaches a predetermined level, the resilient fluid pressure-energized valve element <NUM> (e.g., U-cup seal) is activated to open to communicate pressurized fluid from the cover chamber <NUM> to the control chamber <NUM> until the pressure therebetween is substantially equalized and/or until the fluid pressure-energized valve element (e.g., U-cup seal) is configured to close based on the pressure differential. When the wheel valve assembly <NUM> is activated and the diaphragm <NUM> is sealingly disengaged from the protruding portion <NUM>, the pressurized air within the control chamber <NUM> does not communicate with the cover chamber <NUM> because the fluid pressure-energized valve element <NUM> (e.g., U-cup seal) prevents such fluid communication.

Claim 1:
A valve (<NUM>) for use in an inflation/deflation system, comprising:
a valve body (<NUM>) having a first inlet/outlet port (<NUM>) fluidly connectable to a second inlet/outlet port (<NUM>);
a valve member (<NUM>) movable within the valve body between a first position and a second position for fluidly connecting or disconnecting the first inlet/outlet port and the second inlet/outlet port; and
a fluid-operated damper (<NUM>) operably connected to the valve member to dampen movement of the valve member from the second position to the first position;
wherein, when in a first state, the first inlet/outlet port is fluidly disconnected from the second inlet/outlet port by the valve member;
wherein the valve is configured to transition to a second state when a fluid pressure at the first inlet/outlet port is at or above a prescribed pressure threshold, and when in the second state the first inlet/outlet port is fluidly disconnected from the second inlet/outlet port;
wherein, when the valve is in the second state, lowering the fluid pressure below the prescribed pressure threshold causes the valve to transition from the second state to a third state;
wherein, when in the third state, the first inlet/outlet port is fluidly connected to the second inlet/outlet port while the damper dampens movement of the valve member from the second position to the first position to maintain the valve in the third state for a prescribed period of time;
wherein the damper includes a damper fluid chamber (<NUM>); wherein the valve further includes a vent passage (<NUM>) fluidly connected to the damper fluid chamber, and a vent valve (<NUM>) configured to open and close the vent passage, such that when the vent passage is opened by the vent valve fluid is permitted to vent from the damper fluid chamber;
wherein the valve body forms a primary chamber (<NUM>), the primary chamber being fluidly connectable to the first inlet/outlet port (<NUM>) and the second inlet/outlet port (<NUM>);
characterised in that the vent passage (<NUM>) fluidly connects the damper fluid chamber (<NUM>) to the primary chamber (<NUM>).