Road speed control with redundant release

摘要

A vehicle road speed control system having a redundant release valve assembly. A solenoid control actuated control valve energized by application of the vehicle brakes dumps the higher pressure side of the servomotor to the lower pressure side to balance the pressures on the power wall. The power wall return spring and the throttle valve return spring respectively return the power wall and the throttle valve to the closed throttle position. If the effective opposed areas of the power wall are substantially different, a bleed orifice is utilized to offset the difference. The servomotor output rod extends through the higher pressure servomotor chamber in two illustrated embodiments and through the lower servomotor pressure chamber in another embodiment.