VALVE ASSEMBLY FOR A TIRE INFLATION SYSTEM

RELATED APPLICATIONS

This application is claiming the benefit, under 35 U.S.C. § 1 lS(e), of the provisional application filed on March 15, 2016, under 35 U.S.C. § 111 (b), which was granted Serial No. 62/308,257, and is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to a valve assembly. In certain embodiments, the invention relates to a valve assembly for a tire inflation system. More particularly, the invention relates to a wheel valve assembly for a tire inflation system.

BACKGROUND OF THE INVENTION

Tire inflation systems can be utilized to manually and/or automatically inflate the pressure within a tire to a desired level. Typically, a tire inflation system utilizes a wheel valve affixed to each wheel for effecting tire pressure adjustments. However, the wheel valves known in the art are complex and expensive to manufacture. Therefore, it would be desirable to provide a wheel valve assembly which overcomes the disadvantages known in the prior art designs.

SUMMARY OF THE INVENTION

Embodiments of a valve assembly for a tire inflation system are described herein. In an embodiment, a valve assembly for a tire inflation system has a housing that has an air supply conduit for fluidly connecting the valve assembly to the tire inflation system. The housing has disposed within a core member that is rotatable under the effect of injection of pressurized air via the air supply conduit and a torsion member connected to the core member to resist rotation of the core member in a predetermined direction. Under the effect of the injection of the pressurized air at a first pressure, the core member is rotatable from a rest position to a first position and, under the effect of the injection of the pressurized air at a second pressure which is greater than the first pressure, the core member is rotatable to a second position.

In an embodiment, a valve assembly for a tire inflation system has a housing, the housing including an air supply inlet for fluidly connecting the valve assembly to the tire inflation system; a core member disposed within the housing with a first core member conduit, a second core member conduit, a third core member conduit, and a fourth core member conduit provided within the core member, and; a torsion member connected to both the housing and the core member to resist rotation of the core member relative to the housing in a predetermined direction.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The above, as well as other advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings in which:

FIG. 1 is a schematic of an embodiment of a tire inflation system in a commercial type vehicle in accordance with the invention;

FIG. 2a is a partial perspective view of an embodiment of a valve assembly in accordance with the invention;

FIG. 2b is an enlarged partial perspective view of a portion of the valve assembly of FIG. 2a;

FIG. 2c is an enlarged partial perspective view of another portion of the valve assembly of FIG. 2a;

FIG. 3 is a perspective view illustrating the valve assembly of FIG. 2a, in a rest state;

FIG. 4 is a perspective view illustrating the valve assembly of FIG. 2a, in the measurement state or inflate state; and

FIG. 5 is a perspective view illustrating the valve assembly of FIG. 2a, in the deflate state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific assemblies illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined herein. Hence, specific dimensions, directions or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless expressly stated otherwise. The term "or" is used herein, unless expressly indicated, in the conjunctive sense, not the disjunctive sense.

Embodiments of a valve assembly are described below. The valve assembly is of the normally closed variety. Preferably, the valve assembly is utilized as a wheel valve and with a tire inflation system, such as in a central tire inflation system, however, the valve assembly can be used in any system with pressure changes. For the purposes of this disclosure, the valve assembly is often indicated in the figures as a wheel valve assembly, however, these examples are not to be limiting and the valve assembly can be used in other aspects of a tire inflation system or in any other system with pressure changes. Advantageously, the valve assembly does not suffer from balancing multiple pressure zones within the assembly.

The embodiments of the invention described herein can be used with any TIS in the art. One such tire inflation system is described herein in further detail to provide context and should not be construed as limiting the invention to just those systems. Additional examples of TISs can be found in U.S. Pat. No. 9,296,264 (issued March 29, 2016) and U.S. Pat. No. 9,493,042 (issued November 15, 2016), the disclosures of which are hereby incorporated by reference in their entirety to the extent permitted by law. Many other examples of TISs exist and will be known to those skilled in the art. The embodiments of the invention described herein are able to be used with any TIS in any type of vehicle.

Tire inflation systems are utilized, for example, to inflate and/or deflate one or more tires of a vehicle (not depicted). The valve assembly described herein may have applications to vehicles for both light and heavy duty and for passenger, commercial, and off-highway vehicles. Furthermore, it would be understood by one of ordinary skill in the art that the valve assembly could have industrial, locomotive, military and aerospace applications. In describing the operation of the tire inflation system the terms "inflate" and "deflate," respectively, refer to an increase and decrease, respectively, of the pressure of the air in a tire or the like. In describing the operation of the valve assembly, the terms "inflate position," "deflate position," and "rest position," are used. The terms relating to the operation of the valve are further described below in the context of the valve structure and operation. Terminology relating to the operation of both the tire inflation system and the valve assembly includes the words specifically mentioned above, derivatives thereof, and words of similar import. In addition, the embodiments will be described in connection with a fluid. For the purposes of description only, the fluid will hereinafter be referred to as air. However, alternative fluids are capable of being utilized in practicing the invention.

A schematic of a tire inflation system 10 that the valve assembly is suitable for use in is illustrated in FIG. 1. The tire inflation system 0 comprises a control unit 12. The control unit 12 is configured to enable determining the tire pressure of one or more wheel assemblies 88 and, if needed, increasing the tire pressure thereof.

The control unit 12 comprises a housing 14. A pneumatic control portion 18 is provided within the housing 14. In addition, there may be an electronic control portion 16 also provided within the housing 14. If an electronic control portion 16 is present, as shown, then preferably, the electronic control portion 16 is provided in an upper portion 20 of the housing 14 and preferably, the pneumatic control portion 18 is provided in a lower portion 22 of the housing 14.

The electronic control portion 16 may include a microprocessor 24 operating under the control of a set of programming instructions, which may also be referred to as software. The electronic control portion 16 may include a memory in which programming instructions are stored. The memory can also store identification codes, or other pre-determined information, tire pressure records and/or user inputs over a period of time.

The electronic control portion 16 may receive input signals from a pressure sensor 26, power supply 28 and one or more additional sensors 29 such as, for example, but not limited to, a load sensor and a speed sensor.

Data or partial algorithmic solutions may also come from other microprocessors 7 which are part of other vehicle subsystems. The load sensor, speed sensor or one or more additional sensors 29 may each be conventional in the art. The pressure sensor 26 may also be referred to as a pressure transducer. The electronic control portion 16 may also receive input signals from an operator control device 30.

The operator control device 30 may allow an operator of the vehicle to exert a certain level of control over the tire inflation system 10. The operator control device 30 may be conventional in the art. The operator control device 30 permits an operator of the vehicle to transmit control signals to the electronic control portion 16 to adjust the tire pressure. This feature may be needed in instances where the automatic adjustment of tire pressure is not satisfactory.

The electronic control portion 16 outputs signals to one or more members of the pneumatic control portion 18. Preferably, the electronic control portion 16 outputs signals to a plurality of central valve assemblies 32, 34, 36, 38 of the pneumatic control portion 18. The output signals may be electrical current. Electrical current can be received by a central valve assembly 32, 34, 36, 38 to place the assembly in an open position or a closed position, respectively. Similarly, electrical current can be removed from the central valve assembly 32, 34, 36, 38 to place the assembly in an open position or a closed position, respectively. The electronic control portion 16 may also output signals to a display device (not depicted). The display device may be included as a part of the operator control device 30 or a freestanding device.

The pneumatic control portion 18 comprises one or more conduits 40, 42 provided within the housing 14 and one or more ports 44, 46 formed in the housing 14. In an embodiment, an air supply port 44 is formed in the lower portion 22 of the housing 14. On a side, the air supply port 44 is in fluid communication with an air supply conduit 40 provided within the housing 14. On an opposite side, the air supply port 44 is in fluid communication with an air supply circuit 50.

The tire inflation system includes a source of pressurized air 52.

Pressurized air is supplied to control unit 12 from the source of pressurized air 52 via the air supply circuit 50. Preferably, the source of pressurized air 52 comprises a reservoir 54 such as, for example, a wet tank. Preferably, a compressor 56 is attached to the vehicle and in fluid communication with the wet tank via a supply conduit 58. The air compressor 56 supplies pressurized air to the wet tank for storage therein. In certain embodiments, a drier 60 is interposed in the air supply circuit 50 for removing water from the air. A filter (not depicted) may also be interposed in the air supply circuit 50.

The pressurized air is utilized to determine the tire pressure and, if needed, open one or more wheel valves 86 and increase or decrease the tire pressure as needed. The pressurized air provided in the air supply circuit 50 and supplied from the source of pressurized air 52 comprises air at a certain pressure. The pressure sensor 26 can measure the pressure of the

pressurized air provided in the air supply circuit 50. It is preferred that at the time the method is practiced that the pressurized air provided in the air supply circuit 50 is at a pressure which is greater than the tire pressure. Preferably, the pressure of the pressurized air provided in the air supply circuit 50 is equal to or greater than the target tire pressure so that the tire pressure can, if needed, be increased to the target tire pressure. In an embodiment, the pressure of the air provided in the air supply circuit 50 is equal to the target tire pressure plus 5 psig or more.

In alternative embodiments, the pressure sensor 26 measures pressure directly form the wheel valve 86, as described in more detail below.

The air supply conduit 40 is provided in and extends from the air supply port 44 into the lower portion 22 of the housing 14. An end of the air supply conduit 40 abuts the air supply port 44 and an opposite end abuts a passage 66 utilized for venting a chamber 68 formed within the housing 14. The air supply conduit 40 may have portions of different diameters. The diameter of the air supply conduit 40 generally decreases in size toward the passage 66. In an embodiment, a portion of the air supply conduit 40 adjacent the air supply port 44 is of a diameter which is greater than that of a portion adjacent the passage 66.

The air supply conduit 40 is attached to and in fluid communication with a central control valve assembly 32, which may be referred to herein as "first central valve assembly." Also, the air supply conduit 40 is attached to and in fluid communication with a central supply valve assembly 34, which may be referred to herein as "third central valve assembly." Preferably, the central control valve assembly 32 and central supply valve assembly 34 are of the solenoid variety. The central control valve assembly 32 and the central supply valve assembly 34 are operable from an open position through a closed position and provided within the housing 14. Preferably, the central control valve assembly 32 and the central supply valve assembly 34 are normally in the closed position. For the purposes of this disclosure, the term "central" valve assembly generically differentiates central valves 32, 34, 36, 38 from wheel valve assemblies 86.

The central control valve assembly 32 is provided with an orifice which is smaller than that of the central supply valve assembly 34. When the central control valve assembly 32 is in the open position, the source of pressurized air 52 is in fluid communication with a first fluid conduit 42. When the source of pressurized air 52 and first fluid conduit 42 are in fluid communication via the central control valve assembly 32, the assembly is utilized to communicate a small flow or bleed of air to the first fluid conduit 42 and/or a fluid control circuit 72, 74. When the central control valve assembly 32 is in the closed position, the first fluid conduit 42 is in fluid communication with the chamber 68. When the first fluid conduit 42 is in fluid communication with the chamber 68 and if pressurized air is within the first fluid conduit 42, venting the first fluid conduit 42 occurs. The first fluid conduit 42 is vented by directing a flow of pressurized air from the first fluid conduit 42 through the central control valve assembly 32 into the chamber 68. When the central supply valve assembly 34 is in the open position, the source of pressurized air 52 is in fluid communication with the first fluid conduit 42. When the source of pressurized air 52 and first fluid conduit 42 are in fluid communication, the central supply valve assembly 34 is utilized to

communicate a flow of air from the source of pressurized air 52 to the first fluid conduit 42. Thus, the central supply valve assembly 34 is utilized to promote air flow from the source of pressurized air 52 to the first fluid conduit 42. In the closed position, the central supply valve assembly 34 prohibits air flow from the source of pressurized air 52 to the first fluid conduit 42.

When the central control valve assembly 32 and the central supply valve assembly 34 are in the open position, the central control valve assembly 32 and the central supply valve assembly 34 are in fluid communication via the air supply conduit 40 and the first fluid conduit 42. Therefore, as noted above, when the central control valve assembly 32 and the central supply valve assembly 34 are in the open position, the source of pressurized air 52 is in fluid communication with the first fluid conduit 42. The pressure sensor 26 is provided within the housing 14 and is in fluid communication with the first fluid conduit 42. The pressure sensor 26 can measure the pressure of the air within the first fluid conduit 42. Thus, when the source of pressurized air 52 is in fluid communication with the first fluid conduit 42, the pressure sensor 26 can measure the pressure of the air from the source of pressurized air 52 by measuring the pressure of the air in the first fluid conduit 42. Also, during certain operations, the pressure sensor 26 may measure the pressure of the air in a fluid control circuit 72, 74 by measuring the pressure of the air in the first fluid conduit 42. In addition, the pressure sensor 26 may be used to measure tire pressure of embodiments of the wheel valve 86 described in more detail below. Once the pressure of the air in the first fluid conduit 42 has been measured, the pressure sensor 26 can send a signal to the electronic control portion 16.

As described above, the first fluid conduit 42 is in fluid communication with the pressure sensor 26, central control valve assembly 32 and central supply valve assembly 34. Also, as described above, the first fluid conduit 42 is selectively in fluid communication with the chamber 68. The first fluid conduit 42 is also attached to and in fluid communication with one or more additional central valve assemblies 36, 38.

As illustrated in FIG. 1 , in certain embodiments, the pneumatic control portion 18 comprises two channel valve assemblies 36, 38. In these

embodiments, a central steer axle channel valve assembly 36, which may be referred to herein as "second valve assembly," and a drive axle channel valve assembly 38, which may be referred to herein as "fourth valve assembly," are each attached to and in fluid communication with the first fluid conduit 42.

Preferably, the central steer axle channel valve assembly 36 and central drive axle channel valve assembly 38 are of the solenoid variety. The central steer axle channel valve assembly 36 and the central drive axle channel valve assembly 38 are operable from an open position through a closed position and provided within the housing 14. Preferably, the central steer axle channel valve assembly 36 and the central drive axle channel valve assembly 38 are normally in the closed position.

When the central steer axle channel valve assembly 36 is in the open position, the first fluid conduit 42 is in fluid communication with a first fluid control circuit 72. Preferably, the first fluid control circuit 72 is capable of fluid communication with one or more wheel assemblies 88 provided on a steer axle (not depicted) of the vehicle. When the first fluid conduit 42 is in fluid

communication with the first fluid control circuit 72, a flow of air from the source of pressurized air 52 can be directed to the wheel assemblies 88 provided on the steer axle via the first fluid control circuit 72. Thus, the central steer axle channel valve assembly 36 is utilized to promote air flow from the source of pressurized air 52 to one or more wheel assemblies 88. When the central steer axle channel valve assembly 36 is in the closed position, the first fluid control circuit 72 is in fluid communication with the chamber 68. When the first fluid control circuit 72 is in fluid communication with the chamber 68 and if

pressurized air is within the first fluid control circuit 72, venting the first fluid control circuit 72 occurs. The first fluid control circuit 72 is vented by directing a flow of pressurized air from the first fluid control circuit 72 through the central steer axle channel valve assembly 36 into the chamber 68.

When the central drive axle channel valve assembly 38 is in the open position, the first fluid conduit 42 is in fluid communication with a second fluid control circuit 74. Preferably, the second fluid control circuit 74 is capable of fluid communication with one or more wheel assemblies 88 provided on a drive axle (not depicted) of the vehicle. When the first fluid conduit 42 is in fluid communication with the second fluid control circuit 74, a flow of air from the source of pressurized air can be directed to one or more wheel assemblies 88 provided on the drive axle via the second fluid control circuit 74. Thus, the central drive axle channel valve assembly 38 is utilized to promote air flow from the source of pressurized air 52 to one or more wheel assemblies 88. When the central drive axle channel valve assembly 38 is in the closed position, the second fluid control circuit 74 is in fluid communication with the chamber 68. When the second fluid control circuit 74 is in fluid communication with the chamber 68 and if pressurized air is within the second fluid control circuit 74, venting the second fluid control circuit 74 occurs. The second fluid control circuit 74 is vented by directing a flow of pressurized air from the second fluid control circuit 74 through the central drive axle channel valve assembly 38 into the chamber 68.

The first fluid control circuit 72 and the second fluid control circuit 74 are similarly configured. Thus, only certain members of the first fluid control circuit 72 will be described in more detail below. It should be appreciated that as the first fluid control circuit 72 and the second fluid control circuit 74 are similarly configured, the tire inflation system 10 can utilize the fluid control circuits 72, 74 in similar fashions. For example, each fluid control circuit 72, 74 can be utilized to provide fluid communication between one or more wheel assemblies 88 and the control unit 12. Also, as described above, both the first fluid control circuit 72 and the second fluid control circuit 74 may be vented. The first fluid control circuit 72 and the.second fluid control circuit 74 may be vented separately or simultaneously. Thus, certain operations of the tire inflation system 10 will only be described with respect to the first fluid control circuit 72. However, it should be appreciated that the tire inflation system 10 is not limited to utilizing only the first fluid control circuit 72 as described below in performing one or more of the operations described herein.

The first fluid control circuit 72 comprises a fluid conduit 76 and a channel conduit 46. The fluid conduit 76 is provided in the housing 14 and is attached to and in fluid communication with the central steer axle channel valve assembly 36 on an end. On another end, the fluid conduit 76 is attached to and in fluid communication with the channel conduit 46.

The channel conduit 46 is formed in the housing 14. Preferably, the channel conduit 46 is formed in the lower portion 22 of the housing 14. The channel conduit 46 is attached to and in fluid communication with the fluid conduit 76 on a side thereof and a portion 80 of the fluid control circuit 72 which is provided outside of the housing 14 on an opposite side. The portion 80 of the fluid control circuit 72 which is provided outside of the housing 14 may comprise one or more additional fluid conduits 82, a rotary seal assembly 84 and/or a hose assembly (not depicted).

The channel conduit 46 is in fluid communication with one or more wheel valves 86 via the portion 80 of the fluid control circuit 72 which is provided outside of the housing 14. Preferably, each wheel valve 86 in fluid

communication with the channel conduit 46 may be similarly configured and operates in a similar fashion. As such, the configuration and operation of only one wheel valve 86 will be described below.

The wheel valve 86 may be attached to a wheel assembly 88. The wheel valve 86 separates the fluid control circuit 72 from the wheel assembly 88 and is utilized to retain pressurized air therein. Also, the wheel valve 86 allows the wheel assembly 88 to selectively communicate with the control unit 12 via the fluid control circuit 72. Detailed descriptions of the design and function of embodiments of the wheel valve 86 are presented in the next subsection.

Each wheel assembly 88 comprises a tire 90 and a wheel rim 92. The steer axle may be coupled to the wheel rim 92 of one or more wheel

assemblies 88. Similarly, the drive axle may be coupled to the wheel rim 92 of one or more wheel assemblies 88. A space 94 is defined by an outer surface 96 of the wheel rim 92 and an inner surface 98 of the tire 90. The space 94 is configured to house pressurized air.

The pressurized air housed within the space 94 is referred to herein as "tire pressure." Tire pressure is increased by the addition of pressurized air into the space 94 and decreased by the removal of air from the space 94.

Preferably, the tire pressure is equal to a target tire pressure. The target tire pressure can be selected by an operator of the vehicle to be a desired pressure. After the target tire pressure is selected, it can be programmed into the control unit 12 via the electronic control portion 16. The target tire pressure can also be pre-programmed into the control unit 12. To ascertain if the tire pressure is equal to the target tire pressure, the tire pressure is determined. As noted above, the control unit 12 is configured to enable determining the tire pressure. A preferred method of determining the tire pressure is described in Pat. Pub. No. US 20160375730A1 (published December 29, 2016), the disclosure of which is hereby incorporated by reference in its entirety to the extent permitted by law.

If it is determined that the tire pressure is less than the target tire pressure, the tire pressure can be increased. If it is determined that the tire pressure is greater than the target tire pressure, the tire pressure can be decreased. After the tire pressure has been increased and/or decreased, the tire pressure can be determined again as needed. Also, if the tire pressure is equal to the target tire pressure, the tire pressure can be determined again at a later time.

As noted above, the tire pressure is increased by the addition of pressurized air into the space 94 defined by the outer surface 96 of the wheel rim 92 and inner surface 98 of the tire 90. Likewise, the tire pressure can be decreased by release of air from the space 94. The tire pressure of a plurality of wheel assemblies 88 or exactly one wheel assembly 88 can be adjusted to the target tire pressure. Also, it should be appreciated that the tire pressure can be adjusted for the wheel assemblies 88 of the steer axle or drive axle. However, due to differences in the preferred target tire pressures of the wheel assemblies 88 of the steer axle and drive axle, it is preferred that the tire pressures of the wheel assemblies 88 of the aforementioned axles be adjusted separately.

When the tire pressure is to be increased, the wheel valve 86 is urged to an inflate position, further details of which are described below. Urging a wheel valve 86 to an inflate position will be discussed below with respect to one wheel valve 86 which is in fluid communication with the first fluid control circuit 72. It should be appreciated that the steps for urging the wheel valve 86 to an inflate position are applicable to additional wheel valves 86 in fluid communication with the first fluid control circuit 72. Similar steps may be taken for urging one or more wheel valves 86 in fluid communication with the second fluid control circuit 74 to an inflate position.

To open the wheel valve 86, the central control valve assembly 32, central supply valve assembly 34, and central steer axle channel valve assembly 36 are in the open position so that the source of pressurized air 52 is in fluid communication with the wheel valve 86. Fluid communication between the source of pressurized air 52 and the wheel valve 86 is maintained for a predetermined time to open the wheel valve 86 to an inflate position. Once the source of pressurized air 52 is in fluid communication with the wheel valve 86, a flow of pressurized air from the source of pressurized air 52 is directed through the supply conduit 40, central control valve assembly 32, central supply valve assembly 34, first fluid conduit 42 and first fluid control circuit 72 to the wheel valve 86 to urge the wheel valve 86 to the inflate position. The wheel valve 86 is urged to an inflate position due to the pressure of the air supplied by the source of pressurized air 52 acting on the wheel valve assembly 86 in a manner described below. The wheel valve 86 may also be urged to a rest position, as defined below, when desired such as, for example, when the tire pressure has been increased to the target tire pressure.

Once the wheel valve 86 is in the inflate position, the tire pressure can be increased by any number of methods. For example, the tire pressure can be increased by utilizing one or more pulses of pressurized air to add

pressurized air to the space 94. A pulse of air can be provided by placing the air supply conduit 40 in fluid communication with the first fluid control circuit 72 for a predetermined period of time and, at the end of the predetermined period of time, terminating fluid communication between the air supply conduit 40 and the first fluid control circuit 72. The air supply conduit 40 is in fluid

communication with the first fluid control circuit 72 when the central control valve assembly 32, central supply valve assembly 34 and central steer axle channel valve assembly 36 are in the open position. Utilizing one or more pulses of pressurized air to increase the tire pressure helps to prevent overinflation of the wheel assembly 88.

Once in the inflate position, the wheel valve 86 can be maintained in the inflate position for one or more predetermined periods of time to increase the tire pressure to the target tire pressure. After the tire pressure has been increased to the target tire pressure, the wheel valve 86 is urged to the rest position.

When the tire pressure is to be decreased, the wheel valve 86 is urged to a deflate position. Urging a wheel valve 86 to a deflate position will be discussed below with respect to one wheel valve 86 which is in fluid

communication with the first fluid control circuit 72. It should be appreciated that the steps for urging the wheel valve 86 to a deflate position are applicable to additional wheel valves 86 in fluid communication with the first fluid control circuit 72. Similar steps may be taken for urging one or more wheel valves 86 in fluid communication with the second fluid control circuit 74 to a deflate position.

To open the wheel valve 86 to a deflate position, the central control valve assembly 32, central supply valve assembly 34, and central steer axle channel valve assembly 36 are in the open position so that the source of pressurized air 52 is in fluid communication with the wheel valve 86. Fluid communication between the source of pressurized air 52 and the wheel valve 86 is maintained for a predetermined time. Once the source of pressurized air 52 is in fluid communication with the wheel valve 86, a flow of pressurized air from the source of pressurized air 52 is directed through the supply conduit 40, central control valve assembly 32, central supply valve assembly 34, first fluid conduit 42 and first fluid control circuit 72 to the wheel valve 86 to urge the wheel valve 86 to a deflate position.

Once in the deflate position, the wheel valve 86 can be maintained in the deflate position for one or more predetermined periods of time to decrease the tire pressure to the target tire pressure. After the tire pressure has been decreased to the target tire pressure, the wheel valve 86 is urged to the rest position.

In certain embodiments described below, the valve assembly will be referred to as being in a rest state, measurement state, inflate state, or deflate state. The rest state refers to a condition where measuring, increasing or decreasing the tire pressure is not occurring. The measurement state refers to a condition where the tire pressure is being measured. The inflate state refers to a condition where the tire pressure is being increased. The deflate state refers to a condition where the tire pressure is being decreased.

Referring now to FIG. 3-5, the wheel valve 86 comprises a housing 100.

The housing 100 may be attached to a wheel assembly (depicted as 88 in FIG. 1) via one or more fasteners (not depicted). The one or more fasteners are utilized to secure the valve assembly 86 to the wheel assembly 88.

In one embodiment, the housing 100 may be of a generally rectangular shape. In other embodiments, other housing shapes may be utilized. In an embodiment, like those shown in FIGs. 3-5, the housing 100 comprises a base portion 102 and a cap portion 104 which are attached together. Separate seal members (not depicted) may be provided between the base portion 102 and cap portion 104 of the housing 100 to prevent pressurized air from escaping therebetween. In other embodiments (not depicted), the housing 100 may be formed in a unitary manner.

Referring now to FIGs. 2a and 2b, where the cap portion 104 of the housing 100 has been removed for clarity, the wheel valve assembly 86 comprises a torsion member 106. In an embodiment, the torsion member 106 may be a spring. The torsion member 106 is provided in a cavity 108 formed in the base portion 102 of the housing 100. As illustrated in FIG. 2c, the torsion member 106 is attached on a first end 110 to the cap portion 104 of the housing 100. On the opposite end 112, the torsion member 106 is attached to an end surface 114 of a core member 116. The end surface 114 may be of a circular shape.

The core member 116 is positioned adjacent to the torsion member 106. The torsion member 106 provides resistance and closing force to the core member 116. The resistance provided by the torsion member 106 opposes rotation of the core member 116 in a predetermined direction. The core member 116 may be of a generally cylindrical shape. A force chamber 118 is formed in an outer surface 120 of the core member 116. The force chamber 118 may comprise surfaces 119a, 119b, 119c, 119d which are sharply defined.

Under certain conditions, the force chamber 118 is in fluid

communication with a air inlet conduit 122 formed in the cap portion 104 of the housing 100. The air inlet conduit 122 is in fluid communication with a source of pressurized air (e.g., 82 in FIG. 1) via a supply inlet 123. The first fluid conduit 122 and the supply inlet 123 are aligned. On an end, the supply inlet 123 is in fluid communication with the first fluid conduit 122. Preferably, on another end, the supply inlet 123 is in fluid communication with the tire inflation system (see, e.g., FIG. 1 and accompanying description).

When it is desired to change the state of the wheel valve assembly 86, pressurized air is communicated through the air inlet conduit 122 to the force chamber 118. The pressurized air may be communicated to the force chamber 118 at two or more pressures. The pressurized air acts on the force chamber 118 to rotate the core member 116 within the housing 100. The core member 116 rotates about an axis of rotation A which extends through the center of the core member 1 6. Rotation of the core member 116 changes the state of the wheel valve assembly 86. The rotation of the core member 116 by the pressurized air communicated through the air inlet conduit 122 to the force chamber 1 8 is opposed by the resistance and closing force provided by the torsion member 106.

At a first pressure, the pressurized air acts on the force chamber 118 to rotate the core member 116 a first predetermined amount. Rotation of the core member 116 via the first pressure of the pressurized air places the wheel valve assembly 86 into the inflate or measurement state, as shown in FIG. 4. At a second pressure, the pressurized air acts on the force chamber 118 to rotate the core member 116 a second predetermined amount. Rotation of the core member 116 via the second pressure of the pressurized air places the wheel valve assembly 86 into the deflate state, as shown in FIG. 5. Preferably, the second pressure is greater than the first pressure.

The air inlet conduit 122 is in fluid communication with a second conduit 124 formed in the cap portion 104 of the housing 100. The second conduit 124 may be in a perpendicular relationship with the air inlet conduit 122. A first housing conduit 126 is in fluid communication with the second conduit 124. The first housing conduit 126 is also formed in the cap portion 104 of the housing 100 and is in a perpendicular relationship with the second conduit 124. When the wheel valve assembly 86 is in an inflate or measurement state, as is shown in FIG. 4, the first housing conduit 126 is aligned with a first core member conduit 128.

The first core member conduit 128 is formed in the core member 116 and may be of a generally cylindrical shape. The first core member conduit 128 is in a spaced apart and parallel relationship with a second core member conduit 130. The second core member conduit 130 is formed in the core member 116 and may be of a generally cylindrical shape. When the wheel valve assembly 86 is in an inflate or measurement state, the first core member conduit 128 is in fluid communication with the second core member conduit 130 via a passage 132 formed in the core member 116. Also, as illustrated in FIG. 4, when the wheel valve assembly 86 is in an inflate or measurement state, the second core member conduit 130 is aligned and in fluid communication with a channel conduit 134. Alignment of the second core member conduit 130 and the channel conduit 134 allows pressurized air to be transferred to or removed from the tire 90.

The channel conduit 134 is provided through the cap portion 104 of the housing 100. The channel conduit 134 may be of a cylindrical shape. The channel conduit 134 is in fluid communication with the tire 90. The channel conduit 134 may be in fluid communication with the tire 90 via another fluid conduit (not depicted). The fluid conduit may be provided through the wheel rim 92 or external to the wheel assembly 88.

A third core member conduit 136 is formed in another portion of the core member 116. The third core member conduit 136 may be of a generally cylindrical shape. The third core member conduit 136 is in a spaced apart and parallel relationship with a fourth core member conduit 138. The fourth core member conduit 138 is formed in the core member 116 and may be of a generally cylindrical shape. When the wheel valve assembly 86 is in a deflate state, as is illustrated in FIG. 5, the third core member conduit 136 is aligned with and in fluid communication with the channel conduit 34. Alignment of the third core member conduit 136 and the channel conduit 134 allows pressurized air to be removed from the tire 90. The third core member conduit 136 is also in fluid communication with the fourth core member conduit 138 via a passage formed in the core member 116.

Also, as illustrated in FIG. 5, when the wheel valve assembly 86 is in the deflate state, the fourth core member conduit 138 is aligned and in fluid communication with an atmosphere conduit 140. Alignment of the fourth core member conduit 138 and the atmosphere conduit 140 allows pressurized air to be removed from the tire 90 to atmosphere.

The atmosphere conduit 140 is provided through the cap portion 104 of the housing 100. The atmosphere conduit 140 may be of a cylindrical shape. The atmosphere conduit 140 is in fluid communication with the atmosphere. The atmosphere conduit 140 may be in fluid communication with the

atmosphere via another fluid conduit (not depicted).

When the wheel valve assembly 86 is in a rest state, as is illustrated in

FIG. 3, the third core member conduit 136 is not aligned or in fluid

communication with the channel conduit 134. Also, when the wheel valve assembly 86 is in a rest state, the second core member conduit 30 is not aligned or in fluid communication with the channel conduit 134. However, the third core member conduit 136 and the second core member conduit 130 may be maintained in a generally perpendicular relationship in the rest state, inflate or measurement state, and the deflate state. Each port (122, 126, 134, 140) formed in the cap portion 104 of the housing 100 has a seal (not depicted) provided on the inside diameter of the port. In an embodiment, each seal is similar to the seals which are utilized in ball valves. The seals allow a sharp edge to pass into each port without damaging the seal. Shown as 142 are ball valve seals to prevent air from leaking out of the wheel valve assembly 86. In addition, there may be circumferential seal members 144 provided between the core member 116 and the housing 100 to prevent air leakage between conduits 128 and 130 or 136 and 138.

Operation of the valve assembly will now be discussed with reference to FIGs. 3-5.

As described above, in the rest state illustrated in FIG. 3, the second core member conduit 130 and the third core member conduit 136 are not aligned with or in fluid communication with the channel conduit 134. Also, in this state, the fourth core member conduit 138 is not aligned or in fluid communication with the atmosphere conduit 140 and the first core member conduit 128 is not aligned or in fluid communication with the first housing conduit 126.

In order to move from the rest state to the measurement state or the inflate state illustrated in FIG. 4, a flow of pressurized air is directed from a source of pressurized air (e.g. 82) through the tire inflation system (an example of which is shown in FIG. 1 to the supply inlet 123. The flow of pressurized air is at a first pressure. The wheel valve assembly 86 will remain in the inflate or measurement state as long as pressurized air is provided in the supply inlet 123.

From the supply inlet 123, the pressurized air is directed to the air inlet conduit 122. The flow of pressurized air is provided to the first conduit122 at a first pressure and acts on the force chamber 118 to rotate the core member 116 a predetermined amount. For example, in an embodiment, the core member 116 rotates 45 degrees about the axis of rotation A. Rotation of the core member 116 at the first pressure, allows the first housing conduit 126 to be aligned and in fluid communication with the first core member conduit 128 and the second core member conduit 130 to be aligned and in fluid

communication with the channel conduit 134.

In the measurement state, pressurized air from the tire 90 flows to the channel conduit 134. From the channel conduit 134, the pressurized air flows into the second core member conduit 130 and into the core member 116. From the core member 116, the pressurized air flows into the first housing conduit 126. From the first housing conduit 126 the pressurized air is transferred to the pneumatic control unit 18 via the second conduit 124 and the supply inlet 123 for measurement by the pressure sensor 26.

In the inflate state, pressurized air from the source of pressurized air 52 flows to the supply inlet 123. From the supply inlet 123, the pressurized air flows into the second conduit 124 and the first housing conduit 126 to the first core member conduit 128. From the first core member conduit 128, the pressurized air is transferred to the second core member conduit 130 via the passageway 132 in the core member 116. From the second core member conduit 130, the pressurized air flows into the channel conduit 134 to the tire 90.

In order to move to the deflate state illustrated in FIG. 5 from the rest state, measurement state or inflate state, a flow of pressurized air is directed from the source of pressurized air 52 through the tire pressure management system (see, e.g., FIG. 1) to the supply inlet 123. The flow of pressurized air is provided at a second pressure. The second pressure of the flow of pressurized air is greater than the first pressure thereof. The wheel valve assembly 86 will remain in the deflate state as long as te second pressure of the flow of pressurized air is provided to the supply inlet 123.

From the supply inlet 123, the pressurized air is directed to the air inlet conduit 122. The flow of pressurized air is provided to the air inlet conduit 122 at the second pressure and acts on the force chamber 118 to rotate the core member 116 a second predetermined amount. For example, in this

embodiment, the core member 116 may rotate 45 degrees about the axis or rotation A from its position in the measurement or inflate state. Rotation of the core member 116 at the second pressure, allows the third core member conduit 136 to be aligned and in fluid communication with the channel conduit 134 and the fourth core member conduit 138 to be aligned and in fluid communication with the atmosphere conduit 140.

In the deflate state, pressurized air from the tire 90 flows to the channel conduit 134. From the channel conduit 134, the pressurized air flows into the third core member conduit 136 and into the passageway 132 of the core member 116. From the passageway 132 in the core member 116, the pressurized air flows into the fourth core member conduit 138. From the fourth core member conduit 138 the pressurized air is directed to the atmosphere via the atmosphere conduit 140.

To move the wheel valve assembly 86 from the measurement state, inflate state or deflate state back to the rest state, the pressurized air provided to or in the supply inlet 123 is vented. Venting the supply inlet 123 removes the pressurized air from the supply inlet 123 which allows the resistance provided by the torsion member 106 to rotate the wheel valve assembly 86 back to the rest state illustrated in FIG. 3. Due to the curvilinear features of the on the core member 116, the forces applied to the core member 116 cancel each other except for the force applied to the force chamber 118 where there are flat faces (e.g., 119b, 119c, and 119d) in the X and Y direction of which the resultant force should apply a torque and cause the core member 116 to rotate back and return the wheel valve assembly 86 to the rest state shown in FIG. 3.

While the embodiments of the valve assembly described herein are shown as wheel valve assemblies, it is within the bounds of the invention to use the embodiments described herein in any situation where varying amounts of fluid pressure can be harnessed to change the function of the valve. One other, non-limiting, contemplated use may be for transmissions.

From the foregoing detailed description, it will be apparent that various modifications, additions, and other alternative embodiments are possible without departing from the true scope and spirit. The embodiments discussed herein were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one ordinary skill in the art to use the invention in various embodiments and with various modifications as are suited to the particular use contemplated. As should be appreciated, all such modifications and variations are within the scope of the invention.