WO2011130747A1

WO2011130747A1 - Air hose with pressure relief valve

Info

Publication number: WO2011130747A1
Application number: PCT/US2011/032918
Authority: WO
Inventors: Mark Kevin Hennig
Original assignee: Equalaire Systems, Inc.
Priority date: 2010-04-16
Filing date: 2011-04-18
Publication date: 2011-10-20

Abstract

A tire inflation system may include a pressurized air supply, a pressure line which is connectable to the pressurized air supply and to a tire, a regulator in fluid communication with the pressurized air supply and a pressure relief valve in fluid communication with the tire. The regulator may automatically maintain the tire at a desired minimum pressure through the pressure line. The pressure relief valve may form part of the pressure line and may function to automatically vent excess air pressure from the tire.

Description

TITLE: AIR HOSE WITH PRESSURE RELIEF VALVE

INVENTOR: Mark Kevin Hennig

RELATED APPLICATION DATA

[001] This application claims priority to U.S. Provisional Patent Application No. 61/324,862, entitled "Air Hose With Pressure Relief Valve" filed April 16, 2010, which is hereby entirely incorporated herein by reference.

BACKGROUND

[002] Automobile tire pressure may vary according to a number of factors, including altitude and temperature. A tire's pressure may rise and fall within a single trip or within a single day depending on the change of altitude experienced during the trip, the temperature range experienced during the trip or the amount of heat generated by normal movement of the tire. An automatic tire inflation system may automatically regulate tire pressure.

SUMMARY

[003] A tire inflation system may comprise a pressure line connectable to a tire and a regulator in fluid communication with a pressurized air supply. The regulator may be capable of automatically maintaining said tire at a desired minimum pressure via fluid communication through the pressure line. The pressure line may further comprise a pressure relief valve in fluid communication with the tire. The pressure relief valve may be capable of automatically venting air to atmosphere when the pressure in the tire exceeds a maximum threshold pressure.

[004] A method may comprise providing a pressure line connectable to a tire. The pressure line may comprise a pressure relief valve in fluid communication with the tire. The pressure relief valve may be capable of automatically venting air to atmosphere when the air pressure in the tire exceeds a maximum threshold pressure. The method may also comprise providing a regulator in fluid communication with a pressurized air supply and the pressure line. The regulator may be capable of automatically maintaining said tire at a desired minimum pressure via fluid communication through the pressure line.

[005] A tire inflation system may comprise means for conveying pressurized air from a pressurized air source to a tire and means for regulating the air pressure of the pressurized air conveyed by the means for conveying pressurized air. The means for regulating the air pressure may be capable of automatically maintaining said tire at a desired minimum pressure via fluid communication through the means for conveying pressurized air. Additionally, the means for conveying pressurized air may further comprise means for pressure relief. The means for pressure relief may be in fluid communication with the tire and may be capable of automatically venting air to atmosphere when the pressure in the tire exceeds a maximum threshold pressure.

BRIEF DESCRIPTION OF THE FIGURES

[006] FIG. 1 illustrates a perspective view of an axle and one embodiment of an automatic tire inflation system.

[007] FIG. 2 illustrates a cross-section of one embodiment of an automatic tire inflation system.

[008] FIG. 3 illustrates a partial cutaway view of one embodiment of an automatic tire inflation system.

DETAILED DESCRIPTION

[009] Referring now to FIGS. 1 and 2, the reference numeral 10 generally indicates an exemplary automatic tire inflation system as installed in a vehicle having an axle 12 and a spindle 13 portion thereof. A wheel assembly 11 may include a hub 14 which may rotate on inner and outer bearings 16 and 18, and may support a wheel and tire (not shown).

[0010] The exemplary automatic tire inflation system 10 may include an air pressure supply 28, which may be a normal component on a truck or vehicle for various purposes such as brakes, a pressure protection valve 30, a flow switch 32 and an indicator or warning system light 34. The air pressure supply 28 may include the axle 12, which may be hollow and may be connected to air pressure supply 28 through line 36 and may include an internal plug 37 (shown in FIG. 2) at each end of the axle 12 whereby the interior of the axle 12 forms part of the air pressure supply 28. A regulator (not shown) may be set to reduce the pressure of air from the air pressure supply 28 to be substantially at a desired tire pressure (for example, 120 psi).

[0011] Various types of automatic tire inflation systems may be used, such as those disclosed in U.S. Patent Nos. 6,698,482; 6,105,645, 6,325,124, 6,325,123, 7,302,979, 6,269,691, 5,769,979, 7,273,082, 6,145,559, 7,270,365, and 6,425,427, and U.S. Pat Pub. Nos. 2009/0241655 and 2009/0266460, the disclosures of which are incorporated herein by reference. The automatic tire inflation system of U.S. Patent No. 6,698,482 is described herein by way of example only.

[0012] The reference numeral 100 (shown in FIG. 2) generally indicates a rotary air connection for supplying air from an air pressure supply 28 on a vehicle in an automatic tire inflation system 10 for a vehicle to the rotating tires. The numeral 13 generally indicates an axle end or spindle. A hub cap 114 (shown in FIG. 2) is provided at each end of the axle 12 mounted to the hubs 14 for retaining lubricant in the wheel bearings 16 and 18. An air pressure supply 28, either directly in the axle 12, or through an interior conduit (not shown) in the inside of the axle 12, may supply air to a rotary air connection 100 through the inside of the axle 12. A rotary union generally indicated by the reference 120 may be supported and positioned in the center end of the spindle 13, such as by press-fit plug 37, and may sealingly engage the interior of the axle 12 by a seal 124 if air is injected directly into the inside of the axle 12. The rotary union 120 may have a first stationary part 128 having a passageway 136 therethrough. The passageway 136 may be in communication with the air pressure supply 28 through a filter 116. A first resilient rotary seal 138 may be supported in the passageway 136 and may encircle the passageway 136. The rotary union 120 may include a second rotatable part including a tubular member 142 having a first end 144 and a second end 146. The second end 146 may be coaxially extendable through and may be longitudinally and rotationally movable in the passageway 136, may sealably engage the rotary seal 138, and may be in communication with the air pressure supply 28. The first end 144 of the tubular member 142 may be sealably and rotatably connected to the air connection or tee-body 152 on the hub cap 114 through a rotary seal 150. The first end 144 of the tubular member 142 may include a shoulder 102 which includes a bearing 101. The air connection 152 or tee-body may be provided on the hub cap 114 for connection to one or more tires (not shown) at the end of axle 12. [0013] In some embodiments, a fitting 60 may be attached to each opening 62 in the air connection 152, thus forming a tee-shaped connection. The fitting 60 may be provided with a fitting valve 64 that may be biased closed by a spring 65 when no air hose 70 is attached to the fitting 60. The fitting valve 64 may be sealed to the fitting 60 by an o-ring 67 when in the closed position.

[0014] In some embodiments, one or more air hoses 70 may be provided to communicate air between the air connection 152 and the tires (not shown). An air hose 70 may be attached to each fitting 60. A threaded nut 72 may be rotatably mounted to a first end 74 of the air hose 70. The first end 74 may comprise a post 76 that may depress the fitting valve 64 when the first end 74 is threadably mounted to the fitting 60. A first Schrader valve 78 may be mounted in the post 76, and may be positioned so as to allow air to pass from the air connection 152 into the air hose 70.

[0015] A second end 80 of the air hose 70 may be threadably attached to a conventional tire stem (not shown) having a tire valve (not shown). The second end 80 may be provided with a pin 82 positioned to contact the tire valve when the second end 80 is attached to the tire stem, thereby maintaining the tire valve in an open position so as to allow flow of air to and from the tire.

[0016] A pressure relief valve 84 may be positioned in the air hose 70 downstream of the first Schrader valve 78. In some embodiments, the pressure relief valve 84 may be comprised of a ball 85 urged by a spring 90 so as to seal the air relief port 93 from the air hose channel 91. In the embodiment of FIG. 3, the pressure relief valve 84 may be mounted to a side of the first end 74 of the air hose 70. In other embodiments, the pressure relief valve 84 may be configured into a more streamlined form. The pressure relief valve 84 may be of any suitable configuration, and may be positioned close to the air connection 152 so as to reduce the potential for mass asymmetry about the axis of tire rotation. In some embodiments, the pressure relief valve 84 and air hose 70 may be manufactured as a unitary part. In some embodiments, the pressure relief valve 84 may be removably mounted to the air hose 70. Removable mounting may allow ready repair or replacement of the pressure relief valve 84 without having to replace the air hose 70.

[0017] In some embodiments, a second Schrader valve 86 may be provided downstream of the first Schrader valve 78. In such embodiments, when the first end 74 of the air hose 70 is attached to a fitting 60, and the second end 80 of the air hose 70 is attached to the tire stem (not shown), the second Schrader valve 86 may allow tire pressure to be checked without removing the air hose 70 from the tire stem.

[0018] In operation, the hub cap 114 may rotate with the wheels relative to the first stationary part 128 of the rotary union 120. The tubular member 142 may rotate in rotary seal 138 and/or rotary seal 150 as the hub cap 114 rotates. Air may be supplied through the first stationary part 128 of the rotary union 120, and may be communicated to the air connection 152 through tubular member 142. When the first end 74 of the air hose 70 is not attached to the fitting 60, the fitting valve 64 may remain closed, thus preventing air from escaping from the air connection 152 into the atmosphere. When the second end 80 of the air hose 70 is attached to the tire stem, and the first end 74 of the air hose 70 is attached to the fitting 60, then air may pass through the fitting valve 64 to the first Schrader valve 78.

[0019] In some embodiments, the air flowing out through the fitting valve 64 may be substantially at a target tire pressure (for example, 120 psi). If the air pressure in a tire is lower than the target pressure, then the first Schrader valve 78 may open to allow air to flow through the air hose 70 and pressure relief valve 84 into the tire. If the air pressure in a tire is substantially at or above the target pressure, then the first Schrader valve 78 may remain closed, thus preventing air from flowing through the air hose 70 and pressure relief valve 84 into the tire. The first Schrader valve 78 may have a default bias force, such as from a valve spring, that allows the valve 78 to open when the pressure difference between the supplied air and the tire air is greater than a certain amount, such as 3 psi. Thus, target tire pressures may be regulated accordingly.

[0020] Tire pressure may vary according to a number of factors, such as altitude and temperature. For example, a stationary tire's temperature may rise as night turns to day, and thus raising the tire pressure. Likewise, a tire's temperature may rise during use, thus raising tire pressure. Or, a tire's pressure may rise as atmospheric conditions change, such as when low-pressure weather systems form. A tire's pressure may also rise when traveling from a lower altitude to a higher altitude. Thus, tire pressure may be greater than the automatic tire inflation system's target pressure, often many times throughout the day. In such cases, air may flow from the tire back through the air hose 70 and escape through the pressure relief valve 84. In some embodiments, the pressure relief valve 84 may be set so as to release air when the tire overpressurization reaches a certain target, such as 10 psi. Thus, if the target tire air pressure is set at 120 psi, the pressure relief valve 84 may release air from the tire if the tire pressure exceeds 130 psi.

[0021] Conversely, a tire's pressure may decrease when traveling from a higher altitude to a lower altitude, or as day turns to night, or as the tire stops moving. When the tire pressure drops below the automatic tire inflation system's target pressure, then the automatic tire inflation system 10 may pressurize the tire. Thus, the automatic tire inflation system 10 and pressure relief valve 84 may function to keep tire pressure substantially within a targeted pressure range.

[0022] The air hose 70 and pressure relief valve 84 configuration may be provided in a variety of configurations. For example, the air hose 70 may be provided with one or more conduits so as to allow air to flow from the air connection 152 through one conduit, and out to the pressure relief valve 84 through another conduit. The pressure relief valve 84 may be positioned along the air hose 70 so as to allow the pressure relief valve 84 to be fixedly mounted to a rigid surface, such as the hub cap 114. For automatic tire inflation systems that pass air through a conduit in the hub cap 114, such as that disclosed in U.S. Pat. Pub. No. 2009/0283190, one or more pressure relief valves 84 may be built into the hub cap 114, or manufactured as an integral part of the hub cap 114.

[0023] The air hose 70 and pressure relief valve 84 configuration may be used with a variety of automatic tire inflation systems, such as those in connection with sealed or unsealed trailer axles, truck drive axles and truck steer axles.

[0024] Tire pressure variation may be particularly pronounced in single-wide tires. Some heavy transporters may replace the typical dual tire configuration at each end of the axle 12 with a single wide-base tire to reduce weight and tire wear. For such single-wide configurations, an air hose 70 having a pressure relief valve 84 may be particularly beneficial.

[0025] 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 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, or 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. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods or steps.

Claims

CLAIMS What is claimed is:

1. A tire inflation system comprising: a. a pressure line connectable to a tire; b. a regulator in fluid communication with a pressurized air supply, the regulator capable of automatically maintaining said tire at a desired minimum pressure via fluid communication through the pressure line; and c. wherein the pressure line further comprises a pressure relief valve in fluid communication with the tire, the pressure relief valve capable of automatically venting air to atmosphere when the pressure in the tire exceeds a maximum threshold pressure.

2. The tire inflation system of claim 1 , wherein the pressure line further comprises a first Schrader valve and wherein the pressure relief valve is positioned downstream of the first Schrader valve.

3. The tire inflation system of claim 1 , wherein the pressure relief valve comprises a ball which is urged by a spring to seal an air relief port.

4. The tire inflation system of claim 1 , wherein the pressure relief valve is positioned in close proximity to a rotational axis of the tire.

5. The tire inflation system of claim 1 , wherein the pressure relief valve is removably mounted to the pressure line.

6. A method comprising: a. providing a pressure line connectable to a tire, wherein the pressure line comprises a pressure relief valve in fluid

communication with the tire, the pressure relief valve capable of automatically venting air to atmosphere when air pressure in the tire exceeds a maximum threshold pressure; and b. providing a regulator in fluid communication with a pressurized air supply and the pressure line, the regulator capable of automatically maintaining said tire at a desired minimum pressure via fluid communication through the pressure line.

7. The method of claim 6, further comprising securing the pressure line to the tire and the pressurized air supply.

8. The method of claim 7, further comprising allowing pressurized air to communicate between the pressurized air supply, the regulator, and the tire such that the pressure in the tire is not substantially lower than the pressure supplied by the regulator.

9. The method of claim 8, further comprising venting air to atmosphere when the air pressure in the tire exceeds the maximum threshold pressure.

10. A tire inflation system comprising: a. means for conveying pressurized air from a pressurized air source to a tire; b. means for regulating the air pressure of the pressurized air

conveyed by the means for conveying pressurized air, the means for regulating the air pressure capable of automatically maintaining said tire at a desired minimum pressure via fluid communication through the means for conveying pressurized air; and c. wherein the means for conveying pressurized air further comprises means for pressure relief, wherein the means for pressure relief is in fluid communication with the tire, wherein the means for pressure relief is capable of automatically venting air to atmosphere when the pressure in the tire exceeds a maximum threshold pressure.