An air suspension system for a vehicle having a supporting frame structure and first and second wheels on at least one side of the vehicle, the air suspension system comprising:
- a) first and second air bags operatively associated with the first and second wheels, respectively, to control relative movement between the first and second wheels and the supporting frame structure;
- b) a manifold including opposing first and second end walls defining a space thereinbetween, the first end wall having a first fluid passageway formed therethrough and the second end wall having a second fluid passageway formed therethrough, wherein a first inlet of the first fluid passageway is smaller in diameter than a diameter of the first end wall and a second inlet of the second fluid passageway is smaller in diameter than a diameter of the second end wall, thereby forming a shoulder at each of the first and second end walls of the manifold, wherein the first and second inlets do not extend into the defined space, the first and second fluid passageways in fluid communication with the first and second air bags, respectively;
- c) an air flow control structure located between the manifold and each of the first and second air bags, at least a portion of the air flow control structure defined by the shoulders, the air flow control structure configured to cause a restriction on the air flow from the manifold into the first air bag, wherein the amount of the restriction on the air flow varies proportionately to the rate of air flow from the manifold into the first air bag and the air flow control structure further configured to regulate the air flow from the manifold into the first air bag such that an increase in a pressure differential between the manifold and the first air bag results in an increase in the flow rate from the manifold into the first air bag that occurs at a lower rate than the rate of the increase in the pressure differential, thereby controlling the rate of air pressure build-up in the first air bag;
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- d) a pressurizing arrangement including a height valve for admitting pressurized air into or exhausting air from the manifold through a low flow-rate air tube, the height valve actuated by a link connected to a rocker member extending between the first wheel and the second wheel, wherein the link is connected to the rocker member at generally a mid point of the rocker member such that any change in height between the mid point and the height valve results in movement of the link to actuate the height valve to either admit pressurized air into or exhaust air from the manifold, wherein the connection between the low flow-rate air tube and the manifold defines a third inlet into the manifold located between the first end wall and the second end wall of the manifold, the third inlet being smaller in diameter than the diameters of the inlets of the first and second fluid passageways.