Brake proportioning means

Claim 1

IN A HYDRAULIC BRAKING SYSTEM, A MEANS FOR SUBSTANTIALLY EQUALIZING DISPLACEMENT AND EFFECTIVENESS OF A MULTIPLICITY OF FLUID PRESSURE OPERATED MOTORS, SAID MEANS COMPRISING: A VALVE MEANS INCLUDING INLET AND OUTLET PORTS IN A HOUSING CONTAINING A VALVE FOR CONTROLLING FLUID COMMUNICATION THEREBETWEEN WITH A VALVE STEM PROJECTING FROM SAID HOUSING; A VALVE OPERATING LEVER PIVOTALLY ATTACHED INTERMEDIATE ITS ENDS TO SAID HOUSING, SAID LEVER HAVING A SURFACE THEREON THAT IS OPERATIVELY ASSOCIATED WITH SAID VALVE STEM FOR OPERATING SAID VALVE; A LOW-RATE SPRING HAVING ONE END AFFIXED TO SAID LEVER FOR STRUCTURE AND THE OTHER END AFFIXED TO SAID LEVER FOR OPERATING SAID LEVER WHENEVER A VARIATION IN DISTANCE BETWEEN THE SURROUNDING STRUCTURE AND SAID LEVER OCCURS; A MEANS TO VARY THE RATE OF THE LOW-RATE SPRING TO PROVIDE A MULTIPLE STAGE LOADING OF THE VALVE MEANS WHENEVER THE DISTANCE VARIES BETWEEN THE SURROUNDING STRUCTURE AND SAID LEVER TO CAUSE SAID LEVER TO ACTUATE SAID VALVE STEM; A HIGH-RATE SPRING CONNECTING SAID HOUSING TO THE OTHER END OF SAID LEVER TO PRELOAD THE OPERATIVE CONNECTION OF SAID LEVER WITH SAID STEM TO CONTROL THE TRAVEL OF SAID STEM IN CONTROLLING THE FLUIUD COMMUNICATION VIA SAID VALVE MEANS; AND MEANS TO ADJUST THE HIGH-RATE SPRING TO INCREASE OR DECREASE THE PRELOAD ON THE LEVER TO THEREBY REGULATE THE STATIC POSITION OF THE VALVE MEANS.