Adjustable vehicle suspension system with adjustable-rate air spring

An air spring assembly capable of operating at at least three substantially-different nominal spring rates each corresponding to a different nominal spring height, said air spring assembly comprising:

• a first end member having a central axis and a peripheral wall extending about said axis between opposing first and second ends, said first end member including first, second and third spring rate zones axially formed along said peripheral wall;
• a second end member spaced from said first end member;
• and,
• a flexible sleeve secured between said first end member and said second end member at least partially forming a chamber therebetween;
• said first spring rate zone disposed toward said first end, and said first spring rate zone having a first nominal diameter disposed a first nominal distance from said first end such that operation of said air spring assembly in said first spring rate zone corresponds to a first nominal spring rate of said at least three substantially-different nominal spring rates at a first nominal spring height;
• said second spring rate zone disposed adjacent said first spring rate zone in a direction opposite said first end, said second spring rate zone having a second nominal diameter disposed a second nominal distance from said first end, said second nominal distance being greater than said first nominal distance of said first spring rate zone, and said second nominal diameter being greater than said first nominal diameter such that operation of said air spring assembly in said second spring rate zone corresponds to a second nominal spring rate of said at least three substantially-different nominal spring rates that is greater than said first nominal spring rate and a second nominal spring height that is less than said first nominal spring height;
• said third spring rate zone disposed adjacent said second spring rate zone in a direction opposite said first spring rate zone, said third spring rate zone having a third nominal diameter disposed at a third nominal distance from said first end, said third nominal distance being greater than said second nominal distance of said second spring rate zone, said third nominal diameter being greater than said second nominal diameter such that operation of said air spring assembly in said third spring rate zone corresponds to a third nominal spring rate of said at least three substantially-different nominal spring rates that is greater than said second nominal spring rate and a third nominal spring height that is less than said second nominal spring height;
• whereby said nominal spring rate of said air spring assembly is adapted to be selectively increased from said first nominal spring rate to said second nominal spring rate by merely venting a volume of air from said air spring assembly and thereby lowering said nominal spring height from said first nominal spring height to said second nominal spring height, and selectively increased from said second nominal spring rate to said third nominal spring rate by merely venting a further volume of air from said air spring assembly and thereby lowering said nominal spring height from said second nominal spring height to said third nominal spring height.

A method of adjusting between performance modes of a suspension system of a vehicle, said method comprising steps of:

• a) providing a damping member having a variable damping rate and a first actuator operatively associated with said damping member for varying said damping rate, and installing said damping member and said first actuator on said vehicle;
• b) providing an air spring assembly and a second actuator, installing said air spring assembly on said vehicle in operative association with said damping member, and installing said second actuator on said vehicle in operative association with said air spring assembly, said air spring assembly capable of being;
• b1) selectively lowered from a first nominal spring height corresponding to a first nominal spring rate to a second nominal spring height corresponding to a second nominal spring rate that is greater than said first nominal spring rate;
• b2) selectively lowered from said second nominal spring height corresponding to said second nominal spring rate to a third nominal spring height corresponding to a third nominal spring rate that is greater than said second nominal spring rate;
• b3) selectively raised from a third nominal spring height corresponding to said third nominal spring rate to said second nominal spring height corresponding to said second nominal spring rate that is less than said third nominal spring rate;
• and;
• b4) selectively raised from a second nominal spring height corresponding to said second nominal spring rate to said first nominal spring height corresponding to said first nominal spring rate that is less than said second nominal spring rate;
• c) providing a controller adapted to selectively actuate at least said second actuator and installing said controller on said vehicle;
• and,
• d) operating said controller to selectively actuate at least said second actuator to fill or vent a volume of air from said air spring assembly to thereby at least partially adjust said suspension system into one of a first performance mode in which said damping member has a first damping rate within a first damping rate range and said air spring assembly has said first nominal spring rate and said first nominal spring height, a second performance mode in which said damping member has a second damping rate within a second damping rate range and said air spring assembly has a said second nominal spring rate and said second nominal spring height, and a third performance mode in which said damping member has a third damping rate within a third damping rate range and said air spring assembly has said third nominal spring rate and said third nominal spring height.