Patent ID: 8517396

Claim:
A gas spring assembly comprising: a first end member including a wall and a passage extending therethrough; a second end member disposed in spaced relation to said first end member; a flexible wall secured on said first and second end members such that a spring chamber is at least partially defined therebetween; and, a height control system supported on said wall of said first end member, said height control system including: a sensor operative to generate a signal having a relation to a distance between said first and second end members; a valve arrangement in fluid communication with said spring chamber through said passage in said wall of said first end member, said valve arrangement selectively operable between a first condition that permits one of gas transfer into said spring chamber and gas transfer out of said spring chamber, a second condition that permits the other of gas transfer into said spring chamber and gas transfer out of said spring chamber, and a third condition in which said spring chamber is fluidically isolated; and, a fixed-logic control circuit capable of operating at a first response rate when said valve arrangement is in one of said first and second conditions and capable of operating at a second response rate when said valve arrangement is in said third condition with said first response rate being substantially greater than said second response rate; said circuit including an input section and an output section, said input section adapted to receive said signal from said sensor and convert said signal to a reference voltage, said output section operative to compare said reference voltage to a first threshold voltage and a second threshold voltage, said output section adapted to initiate switching of said valve arrangement to said first condition if said reference voltage is greater than said first threshold voltage, and said output section adapted to initiate switching of said valve arrangement to said second condition if said reference voltage is less than said second threshold voltage.