Vehicle spring suspensions

Claim 1

A VEHICLE SPRING SUSPENSION FOR A VEHICLE HAVING A CHASSIS AND ALSO HAVING AN AXLE SUPPORTING A GROUND WHEEL, COMPRISING A PAIR OF PIVOTALLY CONNECTED LEVER ARMS RESPECTIVELY EXTENDING FORWARDLY AND REARWARDLY FROM SAID AXLE, A LONGITUDINALLY DISPOSED BEAM CARRIED BY THE CHASSIS, MEANS FOR PIVOTALLY MOUNTING THE FREE ENDS OF SAID LEVER ARMS FOR ANGULAR MOVEMENT ABOUT FIXED HORIZONTAL AXES AT SPACED POINTS ON SAID BEAM, AND MEANS FOR CONTROLLING THE ANGULAR MOVEMENT OF SAID LEVER ARMS IN RELATION TO SAID BEAM COMPRISING A PLURALITY OF RESILIENT ELEMENTS INTERPOSED BETWEEN THE LEVER ARMS AND THE BEAM, SAID ELEMENTS EXTENDING FROM SAID PIVOTAL MOUNTINGS TOWARD THE VERTICAL AXIAL PLANE OF THE AXLE SO THAT, WITH PROGRESSIVE INCREASE IN LOADING AND CONSEQUENT REDUCTION OF THE INCLUDED ANGLES BETWEEN THE BEAM AND THE LEVER ARMS, THE SURFACE AREA OF THE RESILIENT ELEMENTS WHICH COMES UNDER COMPRESSION, AND CONSEQUENTLY THE SPRING RATE OF THE SUSPENSION ALSO INCREASES PROGRESSIVELY, SAID BEAM HAVING END PORTIONS RESPECTIVELY EXTENDING FORWARDLY AND REARWARDLY BEYOND SAID PIVOTAL MOUNTINGS, AND SAID LEVER ARMS HAVING END PORTIONS RESPECTIVELY EXTENDING BEYOND SAID PIVOTAL MOUNTINGS, AUXILIARY RESILIENT ELEMENTS INTERPOSED BETWEEN THE END PORTIONS OF SAID BEAM AND THE END PORTIONS OF SAID LEVER ARMS TO PRELOAD THE SUSPENSION, THE AUXILIARY RESILIENT ELEMENTS BEING IN COMPRESSION WHEN THE VEHICLE IS UNLOADED TO THEREBY MAINTAIN AN INITIAL COMPRESSION UPON THE FIRST NAMED RESILIENT ELEMENTS OVER RELATIVELY SHORT LENGTHS AND CORRESPONDING AREAS ADJACENT SAID PIVOTAL MOUNTINGS.