Level control valve for automatically keeping constant the vehicle height of a commercial vehicle

A level control valve for stabilizing the chassis height of a motor vehicle with a pneumatic shock absorption system, the level control valve comprising:

• a housing defining a central passageway therethrough,
• an inlet port in said housing for fluid communication between a source of compressed air and the central passageway of said housing,
• an exhaust port in said housing for fluid communication between the central passageway of said housing and atmosphere about said housing,
• a valve seat in the central passageway,
• a double valve body in the central passageway adjacent said valve seat,
• a bellows port in said housing for fluid communication with an air suspension bellows line leading to the pneumatic shock absorption system of the vehicle,
• a bore hole connection adjacent said valve seat for fluid communication with said bellows port,
• a hollow valve tappet movable toward sealed engagement with said double valve body,
• an adjustable drive responsive to the change in vehicle height for moving said valve tappet toward or away from sealing engagement with said double valve body,
• a shutoff and outlet valve adapted to act independently of said adjustment drive and having a larger cross section than the bore hole for rapid lowering of the vehicle structure,
• an outlet seat in said housing adjacent said shutoff and outlet valve, and
• a bypass line leading from said bellows port to said shutoff and outlet valve, said bypass line provided with a non-return valve that opens in the direction of said shutoff and outlet valve.