Abstract: A tire inflation system for a heavy-duty vehicle having a source of fluid pressure, a tire and wheel assembly, and a fluid path. The fluid path includes at least one conduit, a first valve, and a flow detection structure. The conduit provides fluid communication from the source of fluid pressure to the tire and wheel assembly. The first valve is disposed along the fluid path. The flow detection structure is disposed along the fluid path and is arranged in parallel to the first valve.

Abstract: A load-based tire inflation system for a heavy-duty vehicle comprises at least one source of fluid pressure, suspension structure of the heavy-duty vehicle, a tire and wheel assembly and a system to control fluid pressure in the tire and wheel assembly. The suspension structure is located between a frame member and an axle and has a condition indicative of a weight of the heavy-duty vehicle. The tire and wheel assembly is operatively mounted to the axle and is in fluid communication with the source of fluid pressure. The control system controls fluid pressure in the tire and wheel assembly in response to the condition of the suspension structure.

Abstract: A regulator for establishing outlet fluid pressure. The regulator includes a valve body having a fluid pressure inlet in selective fluid communication with a fluid pressure outlet. A pilot pressure inlet is formed in the valve body and in fluid communication with a source of pilot pressure. Valving structure in the valve body establishes outlet fluid pressure as a function of pilot pressure. First adjustable structure within the valve body may establish a minimum outlet fluid pressure threshold without regard to pilot pressure. Second adjustable structure within the valve body may establish outlet fluid pressure offset relative to pilot pressure.

Abstract: A tire inflation system for a heavy-duty vehicle having a source of fluid pressure, a tire and wheel assembly, and a fluid path. The fluid path includes at least one conduit, a first valve, and a flow detection structure. The conduit provides fluid communication from the source of fluid pressure to the tire and wheel assembly. The first valve is disposed along the fluid path. The flow detection structure is disposed along the fluid path and is arranged in parallel to the first valve.

Abstract: A regulator for establishing outlet fluid pressure. The regulator includes a valve body having a fluid pressure inlet in selective fluid communication with a fluid pressure outlet. A pilot pressure inlet is formed in the valve body and in fluid communication with a source of pilot pressure. Valving structure in the valve body establishes outlet fluid pressure as a function of pilot pressure. First adjustable structure within the valve body may establish a minimum outlet fluid pressure threshold without regard to pilot pressure. Second adjustable structure within the valve body may establish outlet fluid pressure offset relative to pilot pressure.

Abstract: A fluid flow regulator comprises a body, an actuatable switch, and valve structure. The valve structure is disposed within the body and has at least a portion movable between an actuating position and a non-actuating position. The actuating position actuates the switch. The non-actuating position does not actuate the switch.

Abstract: A load-based tire inflation system for a heavy-duty vehicle comprises at least one source of fluid pressure, suspension structure of the heavy-duty vehicle, a tire and wheel assembly and a system to control fluid pressure in the tire and wheel assembly. The suspension structure is located between a frame member and an axle and has a condition indicative of a weight of the heavy-duty vehicle. The tire and wheel assembly is operatively mounted to the axle and is in fluid communication with the source of fluid pressure. The control system controls fluid pressure in the tire and wheel assembly in response to the condition of the suspension structure.

Abstract: A load-based tire inflation system for a heavy-duty vehicle comprises at least one source of fluid pressure, suspension structure of the heavy-duty vehicle, a tire and wheel assembly and a system to control fluid pressure in the tire and wheel assembly. The suspension structure is located between a frame member and an axle and has a condition indicative of a weight of the heavy-duty vehicle. The tire and wheel assembly is operatively mounted to the axle and is in fluid communication with the source of fluid pressure. The control system controls fluid pressure in the tire and wheel assembly in response to the condition of the suspension structure.

Abstract: A vehicle tire inflation system includes an air supply source in fluid communication with multiple tires of the vehicle. A pneumatic conduit extends between and is in fluid communication with the air supply source and the tires. Means are fluidly connected to the pneumatic conduit for enabling selective inflation and deflation of the tires. The means include a first pneumatic circuit for inflation of the tires, and a second pneumatic circuit for deflation of the tires. The second pneumatic circuit is discrete from the first pneumatic circuit and is common to more than one of the tires. The means provides controlled deflation of the tires in the second pneumatic circuit based upon a predetermined condition, preventing deflation of the tires until the vehicle is parked, or limiting the deflation of the tires, which in turn enables the tire inflation system to accommodate a desirable increased pressure in the tires.

Abstract: A constant pressure vehicle tire inflation system includes an air supply source. A first wheel valve is in fluid communication with a first tire of the vehicle, and a second wheel valve is in fluid communication with a second tire of the vehicle. A pneumatic conduit extends between and is in fluid communication with the air supply source and the wheel valves. At least a portion of the pneumatic conduit remains charged with air from at least one of the supply source and the tires. The system includes means for distributing air flow between the pneumatic conduit and the first and second wheel valves, in which the wheel valves and the means selectively maintain fluid communication between the first and second tires and the pneumatic conduit to provide pneumatic balancing between the tires, and the wheel valves provide emergency protection when a tire experiences significant pressure loss.

Abstract: A constant pressure vehicle tire inflation system includes an air supply source. A first wheel valve is in fluid communication with a first tire of the vehicle, and a second wheel valve is in fluid communication with a second tire of the vehicle. A pneumatic conduit extends between and is in fluid communication with the air supply source and the wheel valves. At least a portion of the pneumatic conduit remains charged with air from at least one of the supply source and the tires. The system includes means for distributing air flow between the pneumatic conduit and the first and second wheel valves, in which the wheel valves and the means selectively maintain fluid communication between the first and second tires and the pneumatic conduit to provide pneumatic balancing between the tires, and the wheel valves provide emergency protection when a tire experiences significant pressure loss.

Abstract: A vehicle tire inflation system includes an air supply source in fluid communication with multiple tires of the vehicle. A pneumatic conduit extends between and is in fluid communication with the air supply source and the tires. Means are fluidly connected to the pneumatic conduit for enabling selective inflation and deflation of the tires. The means include a first pneumatic circuit for inflation of the tires, and a second pneumatic circuit for deflation of the tires. The second pneumatic circuit is discrete from the first pneumatic circuit and is common to more than one of the tires. The means provides controlled deflation of the tires in the second pneumatic circuit based upon a predetermined condition, preventing deflation of the tires until the vehicle is parked, or limiting the deflation of the tires, which in turn enables the tire inflation system to accommodate a desirable increased pressure in the tires.

Abstract: A vehicle tire inflation system includes an air supply source in fluid communication with multiple tires of the vehicle. A pneumatic conduit extends between and is in fluid communication with the air supply source and the tires. Means are fluidly connected to the pneumatic conduit for enabling selective inflation and deflation of the tires. The means include a first pneumatic circuit for inflation of the tires, and a second pneumatic circuit for deflation of the tires. The second pneumatic circuit is discrete from the first pneumatic circuit and is common to more than one of the tires. The means provides controlled deflation of the tires in the second pneumatic circuit based upon a predetermined condition, preventing deflation of the tires until the vehicle is parked, or limiting the deflation of the tires, which in turn enables the tire inflation system to accommodate a desirable increased pressure in the tires.

Abstract: A vent system for an axle of a heavy-duty vehicle includes a check valve and an exhaust tube that is connected to the check valve. The check valve includes a first end that is mounted on the axle, a second end, and a body that is disposed between the first and second ends and is in selective fluid communication with the axle interior. The exhaust tube includes a first end that is mounted on the second end of the check valve, and a second end that is open to atmosphere and is in fluid communication with the check valve body. Using any one of a number of types of configurations for the valve body, the vent system selectively exhausts air from the axle interior to atmosphere to relieve buildups of pressure in the axle, while protecting the integrity of the check valve and preventing contaminants from entering the axle.

Abstract: A rotary union is integrated into the interior of a heavy-duty vehicle hub cap. The hub cap includes a cylindrical sidewall, and an outboard wall that is integrally formed with an outboard end of the sidewall, and which extends generally perpendicular to the sidewall. The hub cap also includes a radially-extending flange that is formed on an inboard end of the sidewall, which receives fasteners to mount the hub cap on a wheel hub. The sidewall and the outboard wall form an interior compartment in the hub cap, and a rotary union is mounted to the hub cap in the interior compartment. The rotary union is mounted on the inboard surface of the outboard wall of the hub cap and is in general axial alignment with an axial centerline of a wheel end assembly, providing fluid communication from a tire inflation system to the tires of the vehicle.

Abstract: A vent system for an axle of a heavy-duty vehicle includes a check valve and an exhaust tube that is connected to the check valve. The check valve includes a first end that is mounted on the axle, a second end, and a body that is disposed between the first and second ends and is in selective fluid communication with the axle interior. The exhaust tube includes a first end that is mounted on the second end of the check valve, and a second end that is open to atmosphere and is in fluid communication with the check valve body. Using any one of a number of types of configurations for the valve body, the vent system selectively exhausts air from the axle interior to atmosphere to relieve buildups of pressure in the axle, while protecting the integrity of the check valve and preventing contaminants from entering the axle.

Abstract: A temperature warning system for a vehicle includes a thermal plug disposed on the wheel end assembly of the vehicle. The thermal plug is in fluid communication with an air supply and with a flow sensor. The flow sensor is operatively connected to a warning light or indicator. Excessive heat in the axle spindle end and/or the wheel end assembly causes a fusible material in the thermal plug to melt allowing air to flow from the air supply through the thermal plug thus activating the flow sensor. The flow sensor in turn activates the warning light or indicator alerting the driver of the vehicle of a problem condition at the wheel end assembly and/or axle spindle.

Abstract: A vehicle tire inflation system includes an air supply source in fluid communication with multiple tires of the vehicle. A pneumatic conduit extends between and is in fluid communication with the air supply source and the tires. Means are fluidly connected to the pneumatic conduit for enabling selective inflation and deflation of the tires. The means include a first pneumatic circuit for inflation of the tires, and a second pneumatic circuit for deflation of the tires. The second pneumatic circuit is discrete from the first pneumatic circuit and is common to more than one of the tires. The means provides controlled deflation of the tires in the second pneumatic circuit based upon a predetermined condition, preventing deflation of the tires until the vehicle is parked, or limiting the deflation of the tires, which in turn enables the tire inflation system to accommodate a desirable increased pressure in the tires.

Abstract: A constant pressure vehicle tire inflation system includes an air supply source. A first wheel valve is in fluid communication with a first tire of the vehicle, and a second wheel valve is in fluid communication with a second tire of the vehicle. A pneumatic conduit extends between and is in fluid communication with the air supply source and the wheel valves. At least a portion of the pneumatic conduit remains charged with air from at least one of the supply source and the tires. The system includes means for distributing air flow between the pneumatic conduit and the first and second wheel valves, in which the wheel valves and the means selectively maintain fluid communication between the first and second tires and the pneumatic conduit to provide pneumatic balancing between the tires, and the wheel valves provide emergency protection when a tire experiences significant pressure loss.

Abstract: A multi-stage height control valve for a pneumatic control system of a vehicle includes an air reservoir port, an exhaust port, an air spring port and a pilot port operatively connected to a rotor valve which is in turn operatively connected to the vehicle. The air reservoir port fluidly communicates with an air tank. The air spring port fluidly communicates with the air springs of the vehicle. The exhaust port opens to atmosphere. The pilot port fluidly communicates with a control/warning device such that, when a secondary ride height is reached by the vehicle, the pilot port signals the control/warning device in order to maintain the vehicle at the secondary ride height. The pilot port alternatively provides an air pressure boost in order to quickly re-inflate the air springs of the vehicle to return the vehicle to the primary design ride height.