Apparatus for controlling fuel vapor flow

In a fuel dispensing nozzle for delivering fuel into a fuel tank by way of a fill pipe, said nozzle comprising

• a nozzle body,
• a spout housing,
• a spout extending from said spout housing,
• a fuel conduit defined by said nozzle and leading to said spout,
• a vapor conduit defined by said nozzle, said vapor conduit associated with said spout for withdrawing displaced vapors from the fuel tank being filled and transporting them to a remote vapor collection system, and
• a fuel valve for controlling flow of fuel through said fuel conduit,
• the improvement wherein
• said fuel dispensing nozzle further comprises
• a vapor regulator valve in said vapor conduit operable in response to a predetermined first vapor pressure condition in said nozzle body, said vapor regulator valve comprising a diaphragm mounted in said nozzle with a first surface facing said vapor conduit, said diaphragm blocking said vapor conduit in a first position and not blocking said vapor conduit in a second position, and biasing means urging said diaphragm to said second position, said diaphragm having a second surface facing a chamber, said nozzle further defining a vent linking said chamber with the ambient exterior of said nozzle, and
• vapor flow controlling means comprising
• a vapor flow control valve element disposed for movement within said vapor conduit relative to a valve seat defined by said conduit, a vapor flow orifice between said vapor flow control valve element and said valve seat having an area variable with the position of said vapor flow control valve element, and
• vapor flow control valve element positioning means comprising sealing means associated with said vapor flow control valve element, said sealing means having at least one surface exposed to fuel pressure in said fuel conduit.