Internal combustion engine fuel system minimizing evaporative fuel losses

Claim 1

In combination with an internal combustion engine, an improved volatile liquid fuel storage and delivery system adapted to minimize evaporative fuel losses, comprising: a remote storage tank for volatile liquid fuel comprising a rigid shell, an impervious flexible medium dividing the shell into an air space and a fuel space, said air space being vented to the atmosphere and said flexible medium being adapted to adjust the volume of said fuel space to be substantially the same as the volume of the liquid fuel contained therein, whereby when volatile liquid fuel is stored in the tank, said fuel space is filled principally with liquid and contains only a minor portion of fuel vapors above said liquid fuel; air induction means adapted to generate a partial vacuum to draw air from the atmosphere and to convey said air into said internal combustion engine for combustion therein, the magnitude of said partial vacuum increasing with the volume of air conveyed through said induction means; and conduit means in fluid communication between said air induction means and the fuel vapors above said volatile liquid fuel adapted for passage of said vapors from said fuel tank to said air induction means, whereby said vapors are drawn from the tank for conveying with said air into the internal combustion engine and a partial vacuum is generated in said fuel space thereby drawing and maintaining said flexible medium in close association with the liquid fuel in said tank.