Failed nozzle relief for a mechanically sealed refueling nozzle in a filler tube

Abstract

A fuel tank filler tube has a seal disposed therein for sealing about a refueling nozzle upon insertion in the tube. When the tank is filled and fuel backs up in the filler tube, in the event of failure of the automatic nozzle shutoff, an annular pressure relief valve surrounding the seal opens and provides for by-pass flow around the seal to the upper end of the filler tube. The annular valve includes a rigid ring member with an annular flexible seal attached and is spring biased to the normally closed position.

1 . A fuel tank filler tube assembly comprising: 
 (a) a tube with an enlarged diameter portion at a proximal end thereof and a distal end adapted for fluid connection to a fuel tank;    (b) an annular seal disposed in said proximal end and adapted for sealing about the outer periphery of a refueling nozzle upon insertion therein; and,    (c) an annular relief valve disposed about said seal and operable to permit fuel to bypass said seal upon fuel back-up in the filler tube during refueling and failure of a refueling nozzle to shut off.    
   
   
       2 . The filler tube assembly defined in  claim 1 , further comprising a vapor recirculation port in the wall of the tube downstream of the annular seal.  
   
   
       3 . The filler tube assembly defined in  claim 2 , wherein said port has one end of a vapor recirculation tube attached thereto.  
   
   
       4 . The filler tube assembly defined in  claim 1 , wherein said relief valve includes an annular elastomeric seal member disposed concentrically with respect to said annular seal.  
   
   
       5 . The filler tube assembly defined in  claim 1 , wherein said relief valve includes an annular valve member moveable in an axial direction with respect to the tube.  
   
   
       6 . The filler tube assembly defined in  claim 1 , wherein said relief valve includes an annular moveable valve member biased to a closed position with a coil spring.  
   
   
       7 . The filler tube assembly defined in  claim 7 , wherein said relief valve includes a rigid annular moveable member with an annular flexible seal attached thereto and moveable therewith.  
   
   
       8 . The filler tube assembly defined in  claim 7 , wherein said flexible seal is formed by insert molding.  
   
   
       9 . The filler tube assembly defined in  claim 7 , wherein said flexible seal is formed of elastomeric material.  
   
   
       10 . The filler tube assembly defined in  claim 1 , further comprising a one-way valve disposed in said tube for closing said nozzle seal upon withdrawal of the nozzle.  
   
   
       11 . A method of making a fuel tank filler tube assembly comprising: 
 (a) forming an enlarged diameter portion at a proximal end of a tube;    (b) disposing an annular refueling nozzle seal in said enlarged diameter portion; and,    (c) disposing an annular relief valve about said nozzle seal in said enlarged portion and by-passing the nozzle seal.    
   
   
       12 . The method defined in  claim 11 , further comprising the step of disposing a one-way valve in said tube and closing said nozzle seal upon withdrawal of the nozzle.  
   
   
       13 . The method defined in  claim 11 , wherein said step of disposing an annular relief valve includes disposing a rigid moveable valve member with a flexible annular seal.  
   
   
       14 . The method defined in  claim 13 , wherein said step of disposing a relief valve includes insert molding said flexible annular seal on said rigid valve member.  
   
   
       15 . The method defined in  claim 13 , wherein said step of disposing flexible seal includes forming a seal of elastomeric material.