GAS TANK CAP WITH ROLL-OVER VALVING

摘要

A cap for closing the filler neck of a vehicle fuel tank, the cap comprising a valve housing, a pressurevacuum valve assembly disposed in the housing to vent the tank when the pressure in the filler neck drops below a predetermined subatmospheric level and when the pressure in the filler neck exceeds a first predetermined superatmospheric level, a roll-over valve for closing the pressurevacuum valve assembly when the filler neck is tilted, and an excessive pressure valve or bypassing the pressure-vacuum valve when the pressure in the filler neck exceeds a second and greater predetermined superatmospheric level.