Patent ID: 7028996

Claim:
A height control valve for controlling the relative height between a vehicle frame and a trailing arm suspension comprising a trailing arm having one end pivotally mounted to the vehicle frame and carrying an axle that rotatably mounts ground engaging wheels, and an air spring positioned between another end of the trailing arm and the vehicle frame to resist the rotation of the trailing arm relative to the frame, the height control valve comprising: a housing defining an interior chamber and having an inlet port for fluidly connecting to a source of pressurized air, an air spring port for fluidly connecting to the air spring, and a shaft opening extending through a first wall, the shaft opening forming at least a portion of an exhaust port for fluidly connecting to atmosphere; a manifold cover module removably mounted to a manifold body to enclose the air spring port and the inlet port; a control valve comprising a rotatable disk having a first side which abuts a first wall disposed within the interior chamber, the rotatable disk having a seal formed by pressurized air supplied from the source of pressurized air to the interior chamber, which biases the first side of the rotatable disk against the first wall, the rotatable disk selectively operable between a fill position where the air spring port is fluidly connected to the inlet port to introduce the pressurized air into the air spring, an exhaust position where the air spring port is fluidly connected to the exhaust port to exhaust the pressurized air from the air spring, and a neutral position where the air spring port is fluidly disconnected from both the inlet port and the exhaust port, to thereby control the introduction and exhaustion of air from the air spring to rotate the trailing arm relative to the vehicle frame and adjust the height of the vehicle frame; wherein the seal is formed substantially by the force of the pressurized air supplied from the source of pressurized air to the interior chamber; wherein the rotatable disk is disposed within the interior chamber and fluidly separates the inlet port and the exhaust port, the rotatable disk having a control passage that fluidly connects the air spring port to the inlet port or the exhaust port upon rotation of the rotatable disk; and wherein the air spring port and the exhaust port are positioned on the first wall, and the inlet port is positioned on a second wall wherein the first side of the disk overlies the air spring port and the exhaust port.