HK1191619B - System and method using a pressure reduction valve - Google Patents

Description

System and method for using a pressure relief valve

Cross Reference to Related Applications

Priority is claimed for U.S. patent provisional application No. 61/494,327, filed on 7/6/2011, which is incorporated herein by reference.

Technical Field

The present application relates generally to vehicle automatic tire inflation systems.

Background

Automatic tire inflation systems may be used to control vehicle tire pressure by adding air to the tires of the vehicle. Automatic tire inflation systems may provide pressurized air from a pressurized air source to the tires of a vehicle such that tire pressure is maintained at a desired pressure level whether the tires are stationary or rotating. Automatic tire inflation systems may use a wide variety of regulators, air conduits, and rotary air connections to provide pressurized air to the tires. Automatic tire inflation systems may also use one or more valves to control the direction, speed, and volume of air flow. There is a need for valve arrangements and methods that better control air flow and quickly reduce tire pressure.

Disclosure of Invention

In some embodiments, a wheel end assembly may comprise: a hub cap mounted to a wheel rotatable on an axle of a vehicle; an air pressure supply located within said axle and connected to a pressure source on said vehicle; a rotary union mounted to the hubcap and in fluid communication with the pneumatic pressure supply; a valve stem mounted to the wheel, the valve stem comprising a valve and an auxiliary port; an air hose connected at a first end to the rotary union and at a second end to the valve stem so as to allow air to flow from the air pressure supply through the air hose to the valve stem; and a manually operable valve, an electrically operable valve or an automatic pressure reducing valve, the valve being connected to the auxiliary port. The pressure relief valve may comprise one of a metering valve, a timed valve, or a deceleration valve, or other suitable valve that allows for relatively high air flow.

In some embodiments, a wheel end assembly comprises: a hub cap mounted to a wheel rotatable on an axle of a vehicle; an air pressure supply located within said axle and connected to a pressure source on said vehicle; a rotary union mounted to the hubcap and in fluid communication with the pneumatic pressure supply; a valve stem mounted to the wheel, the valve stem comprising a valve; an air hose connected at a first end to the rotary union and at a second end to the valve stem so as to allow air to flow from the air pressure supply through the air hose to the valve stem; and a pressure relief valve connected to the rotary union.

In some embodiments, a wheel end assembly comprises: a hub cap mounted to a wheel rotatable on an axle of a vehicle; an air pressure supply located within said axle and connected to a pressure source on said vehicle; a rotary union mounted to the hubcap and in fluid communication with the pneumatic pressure supply; a first valve stem mounted to the wheel, the first valve stem comprising a first valve; a second valve stem mounted to the wheel, the second valve stem including a second valve and an auxiliary port; an air hose connected at a first end to the rotary union and at a second end to the first valve stem so as to allow air to flow from the air pressure supply through the air hose to the first valve stem; and a pressure relief valve connected to the auxiliary port of the second valve stem.

In some embodiments, a vehicle may include one or more tires, an automatic tire inflation system configured to automatically inflate the one or more tires to a desired pressure upon actuation, and a pressure relief valve configured to rapidly release air from the one or more tires. A method of controlling air pressure in a vehicle tire may include opening a pressure relief valve to release air from the one or more tires when the automatic tire inflation system is not activated; and actuating the automatic tire inflation system to inflate the one or more tires to a desired air pressure.

In various embodiments, the pressure relief valve may include one of a metering valve, a timing valve, or a deceleration valve, or other suitable valve, such as an electrically or automatically actuated valve, that allows relatively high air flow to allow for rapid tire deflation.

Drawings

FIG. 1 illustrates an embodiment of a vehicle having an automatic tire inflation system;

FIG. 2 illustrates a number of detailed embodiments of an automatic tire inflation system;

FIG. 3 illustrates an embodiment of a rotary air connection;

FIG. 4 illustrates an embodiment of a rotary air connection including a pressure relief valve;

FIG. 5 illustrates an embodiment of a valve including an auxiliary port;

FIGS. 5A and 5B illustrate another embodiment of a valve including an auxiliary port and a sleeve covering the auxiliary port in a closed position;

FIG. 6A illustrates an embodiment of an axle having a single tire, wherein each wheel on which the tire is mounted is equipped with a valve with a pressure relief valve and an auxiliary port;

FIG. 6B illustrates an embodiment of an axle having dual tires, wherein each wheel on which a tire is mounted is equipped with a valve with a pressure relief valve and an auxiliary port;

FIG. 7 illustrates an embodiment of an axle with dual tires, where a first air hose is connected between a first air connection containing a pressure relief valve and a valve, and a second air hose is connected between the valve and a second valve;

FIG. 8 illustrates an embodiment of an axle with dual tires, where each wheel has two valves, one of which includes an auxiliary port and a pressure relief valve;

FIG. 9 illustrates an embodiment of an axle having a single tire with two valves, one standard valve stem and a second valve stem with an auxiliary port and a pressure relief valve.

Detailed Description

As seen in fig. 1, the vehicle 100 may include a truck 102 and a trailer 104. Truck 102 may include one or more drive axles 106 as part of the vehicle powertrain. Truck 102 may further include a steer axle (not shown in detail) having a pivotable spindle, which may provide steering capability for vehicle 100. The trailer 104 may include one or more fixed axles (not shown). Each axle may have one or more wheels 108 mounted thereon. A pneumatic tire 110 may be mounted to each wheel 108.

The vehicle 100 may be provided with an automatic tire inflation system (such as illustrated in more detail in fig. 2-4 and 6A-9) that may use pressurized air from the vehicle air brake system or some other source of pressurized air to maintain the tires at a desired air pressure. An automatic tire inflation system may be used to control the air pressure in one or more tires 110 mounted to a steering shaft (not shown), drive shaft 106, and/or trailer shaft (not shown). An automatic tire inflation system may include one or more air hoses 112 in fluid communication with each tire 110 for communicating air from an air pressure source to one or more tires 110 and for communicating air from one or more tires 110 to the air pressure source.

Figure 2 illustrates in detail various embodiments of an automatic tire inflation system in greater detail. The trailer 200 may include two axles 202, 204. Some trailers 200 may have dual tires 206, 208 mounted at each end of axles 202, 204, as can be seen with respect to axle 202. Other trailers 200 may have a single tire 210 (e.g., a super single tire or a wide base tire) mounted at each end of the axles 202, 204, as can be seen with respect to axle 204. The automatic tire inflation system may generally include a pressure regulator 214, which may be mounted in a control box, and one or more rotary air connections or rotary unions 216, 218, which are mounted in or near the axle ends as described in more detail below. The pressure regulator 214 may receive pressurized air from an air pressure source 220 through a conduit 212. The air pressure source 220 may comprise, for example, a vehicle air brake system air supply, or a booster or booster pump. The pressure regulator 214 may control or increase or decrease the air pressure from the air pressure source 220 to an air pressure level suitable for inflating the tires 206, 208, 210, such as 110 psi. Pressurized air may flow from the pressure regulator 214 through conduit 222 to the axles 202, 204. From the axles 202, 204, air may flow through line 230 to the rotary connections 216, 218, to hoses 224, 232, and to valves 219, 221, 223 connected to tires 208, 210, 206, respectively.

The axles 202, 204 may be wholly or partially solid or hollow and may be configured in a variety of ways. The axles 202, 204 are hollow for illustration purposes only. For example, in some embodiments, the axle may include a solid beam having a spindle (not shown) attached to each end. The axle spindle may be configured to allow mounting of a wheel bearing on which the wheel hub can be rotatably mounted (not shown). In other embodiments, the axle may include a hollow tube having a spindle attached to each end. The spindle may be hollow, resulting in a hollow axle that is open at each end, as can be seen in the embodiments of fig. 3-4. Alternatively, the spindle may be wholly or partially solid, resulting in a hollow axle (not shown) closed at each end.

Referring now to FIG. 3, reference numeral 302 generally designates a rotary air connection on a truck trailer (not shown) in a vehicle automatic tire inflation system for providing air from an air supply 308 (e.g., the air pressure source 220 in FIG. 2) to rotating tires (not shown). Reference numeral 304 generally indicates one axle or spindle of a trailer having: one or more axles 304 having wheels with one or more tires (not shown) at one end; a hubcap 306 at each end of the axle 304, the hubcap 306 for retaining lubricant in the wheel bearings; and an air supply 308 either directly in axle 304 (e.g., a sealed hollow axle as illustrated in axle 204 of fig. 2) or through an internal conduit in the interior of axle 304 (e.g., line 230 as illustrated in axle 202 of fig. 2) to supply air to rotary air connection 302 through the interior of axle 304, such as described in, for example, U.S. patent nos. 5,584,949, 5,769,979, 6,182,727, 6,145,559, and 6,892,778 and U.S. patent publication No. 2009/0283190, the contents of which are incorporated herein by reference in their entirety.

Pneumatic rotary joints, generally designated by reference numeral 310, may be supported and positioned in the center of each end of axle 304 (e.g., in axle plugs 312), such as, for example, the axle plugs disclosed in U.S. patent nos. 6,131,631, 5,584,949, 5,769,979, 6,394,556, 6,892,778, 6,938,658, 6,325,124, and 7,273,082, some embodiments of axle plugs 312 may seatingly engage the interior of axle 304 with seals 314 injecting air directly into the interior of axle 304, and may in turn be sealed from the exterior of rotary joints 310 by sealed connections 316. Other axle plugs 312 may not seal axle 304.

Still referring to fig. 3, the fitting 310 may have a first stationary member 318 having a passage 320 therethrough. The channel 320 may be in communication with an air supply 308 that injects directly into the interior of the axle 304, as described above, or directly into a supply conduit (not shown). A resilient, stationary first rotary seal 322 may be supported in the channel 320 and may surround the channel 320. While conventional O-rings may be used, the rotary seal 322 may be any suitable seal and any suitable material, such as the nitril lip seal, is satisfactory.

Rotary joint 310 may include a second rotatable component comprising an elongated rigid tubular member 324, preferably metal, having a first end 326 and a second end 328. The second end 328 may extend coaxially through the passage 320 and may be longitudinally and rotationally movable therein, may sealingly engage the rotary seal 322, and may be in communication with the air supply 308. An air connection 330 or tee can be mounted or built into the hub cap 306 for connection to one or more tires at the end of the axle 304. The first end 326 of the tubular member 324 may be sealably connected to an air connection or tee 330 on the hubcap 306 by a seal 332. The seal 332 may be any suitable dynamic seal that allows the end 326 to move axially and rotationally, such as a lip seal or an O-ring seal, and may be held in place by a telescoping cover 334. As can be seen in the embodiment of fig. 4, and as may be used in some embodiments of an automatic tire inflation system, a valve spool 408 (e.g., a Schradervalvecore) may be mounted in the T-body 330 to allow one-way air flow from the tubular member 324 through the T-body 330. In such an embodiment, the check valves may be removed from the air hoses 340, 342 (as illustrated in fig. 3) and other locations along the fluid communication path between the tee body 330 and the vehicle tires, thus allowing air to flow around between the tee body 330 and the vehicle tires without being inhibited. In another embodiment of an automatic tire inflation system, air may flow uninhibited back and forth between the vehicle tires and the pressure regulator 214 or source of pressurized air 220. In such an embodiment, a pressure relief valve in fluid communication with the air may be provided at some point along the air conduit between the source of pressurized air 220 and the vehicle tires. For example, a pressure relief valve may be placed at the pressure regulator 214 or at an automatic tire inflation system control box to allow the driver to release air from the vehicle tires connected to the automatic tire inflation system.

In the embodiment of fig. 3, the air connection 330 may have two ports 336, 338. Air hoses 340, 342 may be connected to ports 336, 338, respectively, to allow air connection 330 to be in fluid communication with the tire.

Referring to fig. 3, in operation, air from the air supply 308 may be supplied through the stationary component 318 of the rotary union 310. Air may flow through the tube 324 to the air connection 330. Air may flow from the air connection 330 through one or more hoses 340, 342, each attached at one end to a port 336, 338 and at the other end to a tire (not shown). Air may flow into the tire through the hoses 340, 342, thus pressurizing the tire. If the tire pressure increases beyond the target pressure of the automatic tire inflation system, the automatic tire inflation system will not inflate the tire. Hub cap 306 may rotate with the wheel and rotate relative to axle 304 and/or tubular member 324. The tubular member 324 may move and rotate within the seals 322, 332, compensating for any misalignment between the rotatable hubcap 306 and the first stationary component 318 of the pneumatic rotary union 310. The above description is generally disclosed in U.S. patent nos. 5,769,979 and 6,698,482, which are incorporated herein by reference in their entirety. The present apparatus, systems, and methods may also be operated with other types of automatic tire inflation systems and rotary connections, such as, for example, those provided by Hendrickson, FleetAir, Stemco, Airgo, Col-Ven/Vigia, and others, or those disclosed in U.S. patent publication nos. 2005/0133134, 2008/0185086, 2009/0283190, 2012/0024445, and 2012/0059546, and U.S. patent nos. 6,105,645, 6,244,316, 6,325,123, 6,585,019, 6,698,482, 6,968,882, 7,185,688, 7,207,365, 7,273,082, 7,302,980 (which are incorporated herein by reference in their entirety).

However, as in fig. 2 and 9, heavy trucks and trailers typically use single tires (e.g., ultra single tires or wide base tires) instead of dual tires (i.e., two tires mounted on each axle). Thus, a two axle trailer would have only four single tires instead of eight tires of the same width. Single tires may include tires manufactured by, for example, Michelin, Toyo, Goodyear, Bridgestone, and other tire manufacturers. Tire pressure in a wide base tire may be more affected by temperature, air pressure level, and other factors than in a typical width tire. Tire pressure may vary depending on a number of factors, such as load, height, and temperature. When subjected to heavier loads, the tire pressure will be higher. In another example, stationary tire temperature may increase as night changes to day, thus increasing tire pressure. Likewise, the temperature of the tire may increase in use, thereby increasing tire pressure. Alternatively, the pressure of the tire may increase with changes in atmospheric conditions, such as when a low pressure weather climate is established. The pressure of the tire may also rise as it travels from a lower elevation to a higher elevation. Thus, the tire pressure may be greater than the target pressure for an automatic tire inflation system, which typically occurs multiple times during the day. Conversely, the pressure of the tire may decrease as it travels from a higher elevation to a lower elevation, or as the day changes to night, or as the tire stops moving. When the tire pressure falls below a target pressure of the automatic tire inflation system, the automatic tire inflation system may pressurize the tire. When the tire pressure rises above the target pressure of the automatic tire inflation system, the automatic tire inflation system will not pressurize the tire. However, the tire may maintain increased tire pressure, resulting in premature, uneven tire wear. The dual tire arrangement is subject to the same overpressure phenomenon. Furthermore, different tires on the same trailer or vehicle may be affected by overpressure to different degrees.

For example, a trailer may be placed in the sun at a loading dock, waiting for a truck to pull. The driver may perform a pre-trip check on tire conditions, including air pressure, before or after attaching the truck to the trailer. A pressure relief valve (such as the pressure relief valves illustrated in fig. 4 and 6A-9) may be used to quickly reduce the air pressure to at or below the target pressure of the automatic tire inflation system, rather than attempting to determine if the tires have excessive pressure. It may not matter that the air pressure drops below the target pressure of the automatic tire inflation system because when the truck engine begins to run and the automatic tire inflation system is activated, the automatic tire inflation system will detect a lower than target pressure and automatically pressurize the under-inflated tires. In some such systems, a low pressure warning light may be illuminated to indicate low pressure and remain illuminated until the system inflates the tire to the desired pressure.

Accordingly, in some embodiments, a method of using a pressure relief valve may include deflating vehicle tires when the automatic tire inflation system is not activated. For example, the driver may open the pressure relief valve for a period of about 10 seconds to release about 10psi or more of air pressure from the tire. The driver may open the pressure relief valve for other suitable durations, or until the driver reasonably believes that the tire is not full, or that the air pressure has decreased by a desired amount. If the pressure relief valve comprises a manually operated valve (e.g., a push button or "slide-open" valve), the driver may simply hold the valve open until a confidence is made that the tire has been sufficiently deflated. In other embodiments, if the pressure relief valve comprises a metering or deceleration valve, the driver may manually open the valve and rely on the valve to automatically close after a certain period of time or at a certain pressure. In other embodiments, if the pressure relief valve comprises an electrically operated valve, the driver may electrically open and close the valve, for example by pressing a button in the cab in wired or wireless communication with the valve. The driver may then actuate the tire inflation system, which may occur automatically, for example, when the driver starts the vehicle engine. The tire inflation system will then detect that the tire is low and then operate to inflate the tire to the desired air pressure.

As illustrated in fig. 4, a pressure relief valve 402 may be provided to relieve the tires, whether in a dual or single tire arrangement. In some embodiments, the pressure relief valve 402 may include a push button 404 for manual actuation. The manual pressure reduction valve 402 may be a normally closed valve that may be opened to reduce tire pressure of a tire (not shown). The valve 402 may be one that remains open only when the push button 404 is pressed. In other embodiments, valve 402 may be a deceleration valve, a metering valve, or a timed valve that remains open for a period of time before automatically closing. With e.g. schrader, which is typical for heavy vehicle tiresThe manual pressure reduction valve 402 may allow a greater volume of air to pass through than a standard stem of a cartridge or other cartridge. For example, a standard valve cartridge may allow a tire to deflate about 10psi in about 30 seconds or substantially more, while a manual pressure reduction valve 402 as described herein may allow a tire to deflate about 10psi in about half that time or substantially less (e.g., about 10 seconds). Thus, the manual pressure reduction valve 402 described herein for use in connection with an automatic tire inflation system may permit a driver to relatively quickly reduce air pressure in a tire that may be over-inflated such that the automatic tire inflation system may increase the pressure in the tire to a desired pressureAnd (4) pressure. The driver does not need to know whether any tires contain excess air; in any event, the driver may simply press or actuate the pressure relief valve to quickly deflate the tire, for example, in 10 seconds or less, and rely on the vehicle's automatic tire inflation system to properly pressurize the tire.

Although the manual pressure reduction valves 402, 616, 620, 626, 716, 820, 822, 912 shown in the figures are depicted as "push button" valves, the valves 402, 616, 620, 626, 716, 820, 822, 912 and all other manual pressure reduction valves described and claimed herein may be any suitable type of pressure reduction valve, such as "slide-open" valves (e.g., as illustrated in fig. 5A and 5B), manual lever operated valves, push button valves, bleed-off valves (petcock-typevalve), ball valves, toggle lever operated valves, electrically operated valves (e.g., to allow remote operation), or other automatic valves.

The manual pressure reduction valve 402 may also be used in a single tire configuration. For example, in the embodiment of fig. 2, for a truck trailer having a single tire 210 instead of dual tires, a single air hose 224 may be used to connect the single tire 210 to a port 226 of the rotary union 216. A manual pressure reduction valve 402 may be connected to port 228.

In other embodiments, such as illustrated in fig. 4, for dual tire applications that require the attachment of two air hoses (as seen in fig. 2 with respect to tires 206 and 208) to ports 336 and 338, a third port 406 may be provided in air connection 330 to allow for the connection of manual pressure relief valve 402. For example, ports 336, 338, and 406 may be oriented in any number of suitable ways to balance a large variety of attachments or to accommodate a variety of attachments and hose shapes and sizes.

In yet another embodiment, such as seen in FIG. 5, a valve stem 500 having an auxiliary port 502 (such as the valve stems disclosed in U.S. provisional patent application No. 61/376,144 and PCT/US2011/048760, the disclosures of which are incorporated herein by reference in their entirety) may be used in place of a standard valve stem for a wheel. For example, as seen in the embodiment of fig. 5, a tire valve stem 500 may include a stem portion 504 and a seating portion 506. The seating portion 506 may include a rubber seal 508 configured to allow for embedded seating in a hole in a tire rim. An air filter 510 may be mounted to a base 512 of the seating portion 506. A valve spool 514 (e.g., a schrader spool) can be movably mounted within the stem portion 504. The valve spool 514 may include a one-way valve that permits air to flow in one direction but not the other. An air hose (not shown) connected to the primary port 516 of the valve stem 500 may be equipped with a post 518 to hold the valve cartridge 514 open, allowing air to flow out of the valve stem 500 when the air hose is attached. The stem portion 504 may be equipped with one or more auxiliary ports 502. A manual pressure relief valve (not shown) may be mounted to the auxiliary port 502 of the valve stem 500 to allow the driver to reduce tire pressure as described above without mounting the manual pressure relief valve 402 to the air connection 330, as seen in fig. 4. The use of a valve stem 500 having an auxiliary port 502, wherein a manual pressure relief valve is mounted to the auxiliary port 502, may avoid the need to connect the manual pressure relief valve 402 to the air connection 330.

In other embodiments, a high-flow valve connected to a valve stem auxiliary port (such as the high-flow valves illustrated in fig. 5A and 5B and disclosed in U.S. provisional patent application No. 61/376,144 and PCT/US2011/048760, described above) may be used to quickly release air from a tire. The column 4 may include a sleeve 40 that is translatable along the column 4 to cover and expose one or more auxiliary ports 32. The sleeve may be any suitable rigid or semi-rigid material, such as metal, plastic, rubber, or ceramic. One or more seals 42 may be placed on the stem to allow for sealing engagement of the post 4 and sleeve 40. For example, the seal 42 may be mounted circumferentially around the interior of the sleeve 40 in a suitably sized groove 44. Alternatively, more seals may be mounted circumferentially around the post 4 in suitably sized grooves (not shown). The seal 42 may be positioned adjacent the auxiliary port 32 and may provide a sealing interface with the sleeve 40. The seal 42 may be an O-ring, lip seal, or any suitable seal, and may be any suitable material, such as nitrile or rubber. In the first position, as shown in fig. 5A and 5B, the sleeve 40 may cover the auxiliary port 32, and the seal 42 may provide a sealing interface with the sleeve 40 above and below the auxiliary port 32 to prevent fluid flow through the auxiliary port 32. In a second position (not shown), the sleeve 40 may be disengaged from at least one seal 42 above or below the auxiliary port 32 to allow fluid flow through the auxiliary port 32.

The sleeve 40 is slidably translatable from a first position to a second position, and from the second position to the first position. In one embodiment, the first position may be a default position or a "closed" position, and the sleeve may be biased toward the first position by a spring 46. The first end 48 of the spring 46 may seat against a shoulder 50 of the post. The second end 52 of the spring 46 may seat against a shoulder 54 provided on the inner surface of the sleeve 40. In the default or "closed" position of the sleeve 40, the spring 46 may be slightly compressed to urge the sleeve 40 into that position along the post 4. A locking ring 56 or nut may be provided around the post 4 to prevent the sleeve 40 from translating along the post 4 away from the spring 46. Thus, in the default or "closed" position of the sleeve 40, the spring 46 may force the sleeve 40 against the locking ring 56.

The sleeve 40 may be manually translated from the "closed" position shown in fig. 4 into a second or "open" position (not shown) along the post 4 to allow fluid communication through the auxiliary port 32, e.g., air may pass from the air passage 24 into the atmosphere, or vice versa. Translation of the sleeve 40 from the "closed" position to the "open" position can compress the spring 46 so that when the manual force against the sleeve 40 is released, the sleeve 40 will translate back along the post 4 to the "closed" position.

In some embodiments, a protective skirt or wave 58 may extend from the sleeve 40 to the first end 26 of the column 4. The undulations 58 shown in outline in fig. 5A and 5B may be a resilient material such as rubber, cloth, or silicone. The undulations 58 may be sealed to the sleeve 40 and to the first end 26 of the post 4 to prevent dirt from collecting inside the sleeve 40 and around the spring 46.

In other embodiments, the sleeve 40 may be threadably mounted to the post 4 and may be rotatably translatable along the post 4 with threads (not shown). For example, instead of using a spring 46, the post 4 may be threaded and the interior of the sleeve 40 may be threaded to allow the sleeve 40 to be threadably mounted to the post 4. In some embodiments, the threads may act as a seal. If the sleeve 40 is threaded to the mast 4, the sleeve 40 can be rotated about the mast 4 to effect translation of the sleeve 40 from the "closed" position to the "open" position along the mast 4, and vice versa.

In some embodiments, such as the embodiment disclosed in FIG. 6A, a single tire 602 may be mounted to the axle 606. The rotary air connection 608 may be mounted to a hubcap (not shown) and is in fluid communication with air provided through the axle 606, as described in more detail above. The wheel on which the tire 602 is mounted may be equipped with a valve stem 610 having an auxiliary port (not shown). A first air hose 614 may connect the air connection 608 to a primary port of the valve 610 and a manual pressure reduction valve 616 may be mounted to a secondary port of the valve 610.

In some embodiments, such as the embodiment disclosed in fig. 6B, dual tires 602, 604 may be mounted to an axle 606. The rotary air connection 622 may be mounted to a hubcap (not shown) and is in fluid communication with air provided through the axle 606 as described in more detail above. Each wheel on which a tire 602, 604 is mounted may be equipped with a valve stem 612, 628 having an auxiliary port (not shown). Thus, the valve 628 may be mounted to the outer wheel and the valve 612 may be mounted to the inner wheel. A first air hose 624 may connect the air connection 622 to a primary port of a valve 628, and a manual pressure reduction valve 626 may be mounted to a secondary port of the valve 628. A second air hose 618 may connect an air connection 622 to the primary port of the valve 612 and a manual pressure reduction valve 620 may be mounted to the secondary port of the valve 612. To make it easier for the driver to access the manual pressure reduction valve 620, a third air hose (not shown) may be used to connect the valve 620 to an auxiliary port of the valve 612. The third air hose may be long enough to allow the valve 620 to be positioned outside the outer wheel.

In the embodiment of fig. 7, a first air hose 702 may be connected between an air connection 704 and a valve 706. The valve 706 may have an auxiliary port (not shown) and a second air hose 708 may connect the auxiliary port to a second valve 710. The valve 710 may be a standard valve stem, or may be a valve stem with an auxiliary port (not shown). Hose 708 may be provided with a post to hold valve 710 open so that air may be communicated back and forth between tires 712, 714 through valves 706, 710. A manual pressure relief valve 716 may be mounted to the air connection 704 to allow the driver to deflate both tires 712, 714 on the axle 718 simultaneously.

In other embodiments, the valve 710 may have an auxiliary port (not shown). The hose 702 may be connected between the air connection 704 and the main port of the valve 710. The secondary port of valve 710 may be connected to the primary port of valve 706. Manual pressure reduction valve 716 may be installed within the auxiliary port of valve 706 instead of air connection 704. Alternatively, in addition to being mounted within air connection 704, manual pressure relief valve 716 may be mounted within an auxiliary port of valve 706.

The wheel may have more than one valve stem. For example, some wheels allow two valve stems to be installed. One of the two valve stems may have an auxiliary port, or both valve stems may have an auxiliary port. In some embodiments, the air hose may be connected at one end to an air connection and at the other end to a standard valve stem mounted to the wheel. A second valve stem having an auxiliary port may be mounted to the wheel, and a manual pressure reducing valve may be mounted to the auxiliary port of the second valve stem.

As shown in the embodiment of fig. 8, in embodiments where each of the dual tires 802, 804 is mounted to its own wheel (not shown), respectively, the dual tires are mounted at one end of an axle 806, each wheel may have two valve stems 808, 810, 812, 814. An air hose 816 may be connected between an air connection 818 and the standard valve stem 808. A second air hose 824 may be connected between the air connection 818 and the second standard valve stem 814. A first valve 810 having an auxiliary port may be mounted to the wheel of the outer tire 802 and a second valve 812 having an auxiliary port may be mounted to the wheel of the inner tire 804. The valve 810 may have a manual pressure relief valve 820 mounted to its auxiliary port to allow the driver to manually release air from the outer tire 802. The valve 812 may have a manual pressure relief valve 822 mounted to its auxiliary port to allow the driver to manually release air from the inner tire 804. To make it easier for the driver to access the manual pressure reduction valve 822, a third air hose (not shown) may be used to connect the valve 822 to an auxiliary port of the valve 812. The third air hose may be long enough to allow the valve 822 to be positioned outside the outer wheel.

In a single tire embodiment, such as seen in fig. 9, a single tire 902 may be attached to an axle 914 and may be equipped with a standard valve stem 904 and a second valve 906 having an auxiliary port (not shown). An air hose 908 may be connected between the air connection 910 and the standard valve stem 904, and a manual pressure reduction valve 912 may be provided in an auxiliary port of the second valve 906 to allow the driver to manually release air from the tire 902.

In a further embodiment, the manual pressure reduction valve may be made part of an air hose connecting the air connection with the valve stem.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. For example, while the disclosed apparatus, systems, and methods may be described with reference to a manually or manually actuated pressure relief valve, an electrically actuated valve or other automatic electronic or mechanical valve may be used to accomplish the relatively rapid reduction in air pressure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, systems, or steps.

Claims (8)

1. A wheel end assembly, comprising:

a pneumatic tire mounted to a wheel rotatable on an axle of a vehicle;

a rotary union in sealed fluid communication with a pneumatic pressure supply;

a valve stem mounted to the wheel and in fluid communication with the pneumatic tire, the valve stem comprising a first valve configured to allow pressurized air to flow into the pneumatic tire and a manually operable second valve configured to allow rapid deflation of the pneumatic tire at a flow rate substantially greater than the first valve; and

an air hose connected at a first end to the rotary union and at a second end to the valve stem to allow air to flow from the air pressure supply through the air hose to the valve stem.

2. The wheel end assembly of claim 1, wherein the manually operable second valve comprises one of a metering valve, a timing valve, or a deceleration valve.

3. A wheel end assembly, comprising:

a pneumatic tire mounted to a wheel rotatable on an axle of a vehicle;

a rotary union in sealed fluid communication with a pneumatic pressure supply;

a valve stem mounted to the wheel and in fluid communication with the pneumatic tire, the valve stem comprising a first valve configured to allow pressurized air to flow into the pneumatic tire;

an air hose connected at a first end to the rotary union and at a second end to the valve stem so as to allow air to flow from the air pressure supply through the air hose to the valve stem, and

a manually operable pressure relief valve mounted to the rotary union, the pressure relief valve configured to allow pressurized air to flow from the pneumatic tire, the pressure relief valve further configured to allow a flow rate substantially higher than the first valve.

4. The wheel end assembly of claim 3, wherein the manually operable pressure relief valve comprises one of a metering valve, a timed valve, or a deceleration valve.

5. A wheel end assembly, comprising:

a pneumatic tire mounted to a wheel rotatable on an axle of a vehicle;

a rotary union in fluid communication with a pneumatic pressure supply,

a first valve stem mounted to the wheel, the first valve stem comprising a first valve,

a second valve stem mounted to the wheel, the second valve stem including a second valve and an auxiliary port,

an air hose connected at a first end to the rotary union and at a second end to the first valve stem so as to allow air to flow from the air pressure supply through the air hose to the first valve stem, an

A manually operable pressure relief valve connected to the auxiliary port of the second valve stem.

6. The wheel end assembly of claim 5, wherein the manually operable pressure relief valve comprises one of a metering valve, a timed valve, or a deceleration valve.

7. A method of normalizing air pressure in one or more tires in a vehicle, the vehicle including the one or more tires, an automatic tire inflation system configured to automatically inflate the one or more tires to a desired air pressure upon actuation, and a pressure relief valve configured to rapidly release air from the one or more tires at a flow rate substantially greater than the tires can be inflated, the method comprising the steps of:

opening the pressure relief valve to release air from the one or more tires for an estimated time to reduce the pressure in the one or more tires below the desired air pressure when the automatic tire inflation system is not activated and the pressure in each of the one or more tires is not checked; and

after releasing air from the one or more tires, the automatic tire inflation system is activated to inflate the one or more tires to a desired air pressure.

8. The method of claim 7, wherein the pressure relief valve comprises one of a metering valve, a timed valve, or a deceleration valve.