Load control valve for vehicle air springs

Claim 1

CONTROL VALVE MECHANISM FOR REGULATING THE AIR PRESSURE WITHIN A VEHICLE AIR SPRING FOR MAINTAINING THE VEHICLE FRAME A PREDETERMINED DISTANCE ABOVE THE VEHICLE AXLE COMPRISING A LEVELING VALVE HAVING A CASING ADAPTED TO BE MOUNTED ON THE FRAME AND HAVING AN INLET CAVITY AND PORT AND AN EXHAUST CAVITY AND PORT, A PISTON IN SAID INLET CAVITY MOVABLE BY THE ADMISSION OF FLUID PRESSURE THERETO FROM A FIRST POSITION TO A SECOND POSITION, SPRING MEANS NORMALLY URGING SAID PISTON TO ITS FIRST POSITION, SAID PISTON HAVING AN AXIAL PASSAGE THERETHROUGH AFFORDING A CONNECTION BETWEEN SAID INLET CAVITY AND SAID AIR SPRING, A CHECK VALVE IN SAID PASSAGE TO PREVENT AT ALL TIMES THE BACKFLOW OF AIR FROM SAID SPRING TO SAID INLET CAVITY, EXHAUST PASSAGE MEANS IN SAID CASING AFFORDING A CONNECTION BETWEEN SAID AIR SPRING AND SAID EXHAUST CAVITY, FIRST VALVE MEANS IN SAID CASING MOVABLE INDEPENDENTLY OF SAID PISTON TO CONTROL THE FLOW OF AIR THROUGH SAID INLET AND EXHAUST PASSAGES TO AND FROM SAID AIR SPRING IN ACCORDANCE WITH THE RELATIVE MOVEMENT BETWEEN THE FRAME AND AXLE, AND SECOND VALVE MEANS CONTROLLED BY SAID PISTON WHEN IN ITS FIRST POSITION TO DISCONNECT SAID EXHAUST CAVITY FROM SAID EXHAUST PORT AND CONTROLLED BY SAID PISTON WHEN IN ITS SECOND POSITION TO CONNECT SAID EXHAUST CAVITY AND SAID EXHAUST PORT.