Automotive nozzle-actuated refueling emission system shutoff valve

Claim 1

A fluid flow device for use in connection with a motor vehicle having a fuel-containing line connecting a fuel tank to a portion of the engine fuel combustion system comprising: (a) a first hollow tubular segment adapted to be inserted in a conduit connected to said fuel tank through which conduit liquid fuel ordinarily is introduced into said fuel tank; (b) a first valve seat positioned and dimensioned within said tubular segment sufficiently near one end of segment so as to permit passage therethrough of a fueling nozzle; (c) a flapper pivotably mounted within said tubular segment to seat against said valve seat and seal said seat in the absence of a fueling nozzle being inserted in said valve seat (d) a second tubular segment attached to, and communicating with said first hollow tubular segment. (e) a second valve seat positioned in said second tubular segment; (f) a second valve and valve stem having an upstream side and a downstream side positioned coaxially within said second tubular segment and sealing against said second valve seat and engaging said flapper of (c) so that when the flapper is opened said valve stem is displaced longitudinally; (g) means for urging said second valve and valve stem of (f) into a closed position; (h) means providing a flexible seal between the flapper valve in an open position and said second valve when both are in an open position; (i) a third tubular segment attached near one end to said second tubular segment and communicating with the upstream side of said second valve when said valve is closed and with the downstream and upstream sides when said valve is open, the other end of said third tubular segment communicating with the upper portion of said tank; and (j) a fourth tubular segment attached near one end to said second tubular segment and communicating with the downstream side of said second valve when said second valve is closed and with the downstream and upstream sides when said valve is open.