Dripless fuel dispenser nozzle

Abstract

A fuel dispenser nozzle has a spout assembly for delivery of fuel into a vehicle fill pipe constructed to limit post-fueling dripping to an average of less than about three drops of fuel per fueling event.

1 . A fuel dispensing nozzle, comprising: 
 a nozzle body,    a nozzle spout having a nozzle spout tip extending distally from said nozzle body, said nozzle spout defining a conduit for flow of fuel from said nozzle spout tip into a vehicle fuel tank fill pipe, and    a dam disposed within said nozzle in communication with said conduit and defining a reservoir region for restricting draining of liquid fuel towards said nozzle tip, 
 with said nozzle spout tip engaged in the vehicle fuel tank fill pipe and said nozzle spout disposed at a first angular orientation below horizontal, said dam defines a first volume of said reservoir region for retaining fuel against draining past said dam to drip from said nozzle spout tip, and  
 with said nozzle spout tip disengaged from the vehicle fuel tank fill pipe and said nozzle spout disposed at a second angular orientation below horizontal greater than said first angular orientation below horizontal, said dam defines a second volume greater than said first volume of said reservoir region for retaining fuel against draining past said dam to drip from said nozzle spout tip.  
   
   
   
       2 . The fuel dispensing nozzle of  claim 1 , wherein said dam is disposed within said nozzle spout.  
   
   
       3 . The fuel dispensing nozzle of  claim 1 , wherein said first angular orientation below horizontal is about 30° below horizontal.  
   
   
       4 . The fuel dispensing nozzle of  claim 3 , wherein said first volume of said reservoir region for retaining fuel is about 20 drops.  
   
   
       5 . The fuel dispensing nozzle of  claim 1  or  claim 3 , wherein said second angular orientation below horizontal is up to about 90° below horizontal.  
   
   
       6 . The fuel dispensing nozzle of  claim 5 , wherein said second volume of said reservoir region for retaining fuel is up to about 40 drops.  
   
   
       7 . The fuel dispensing nozzle of  claim 1 , wherein said dam comprises a cylindrical wall member disposed coaxially within said nozzle spout.  
   
   
       8 . The fuel dispensing nozzle of  claim 7 , wherein said cylindrical wall member comprises a cylindrical tubular insert disposed in engagement with the wall of said conduit.  
   
   
       9 . The fuel dispensing nozzle of  claim 1 , wherein a segment of said annular volume is occupied, including in at least a lower region when dispensing fuel.  
   
   
       10 . The fuel dispensing nozzle of  claim 1 , wherein said annular volume is occupied over an arcuate segment, including at least a lower region when dispensing fuel.  
   
   
       11 . The fuel dispensing nozzle of  claim 10 , wherein said arcuate segment extends more than 180°, including at least through said lower region when dispensing fuel.  
   
   
       12 . The fuel dispensing nozzle of  claim 9 ,  claim 10  or  claim 11 , wherein said annular volume is occupied by an insert member.  
   
   
       13 . A fuel dispenser nozzle comprising: 
 a nozzle body for delivering liquid fuel from a fuel dispenser towards a vehicle fuel tank, and    a nozzle spout associated with said nozzle body for delivering liquid fuel from said nozzle body into a vehicle fuel tank fill pipe inclined at approximately 30° down from horizontal,    said nozzle spout having an inner wall surface defining a liquid flow passageway from said nozzle body to a spout tip, said wall surface having a first region extending to said spout tip and being disposed with generally uniform radius about an axis, and a second region upstream from said first region and relatively closer to said nozzle body and being flared in a upstream direction, said second region of said inner wall surface being disposed at a predetermined angle to said axis,    with said spout tip engaged in the vehicle fill pipe and said axis disposed in general alignment with a vehicle fill pipe axis, said inner wall surface in said first region and said second region being disposed at effective angles below horizontal to encourage flow of liquid fuel toward said spout tip,    whereby, when said spout tip is removed from the vehicle fill pipe after a predetermined interval following cessation of flow of fuel from said nozzle body into said liquid flow passageway of said nozzle spout, dripping of residual liquid fuel from said spout tip is limited to a predetermined average number of drops of liquid fuel per fueling event.    
   
   
       14 . The fuel dispenser nozzle of  claim 13 , wherein the predetermined interval of time is approximately 10 seconds.  
   
   
       15 . The fuel dispenser nozzle of  claim 13  or  claim 14 , wherein the predetermined average number of drops of liquid fuel dripped per fueling event is about 3 drops or less.  
   
   
       16 . A fuel dispenser nozzle comprising: 
 a nozzle body for delivering liquid fuel from a fuel dispenser towards a vehicle fuel tank, and    a nozzle spout associated with said nozzle body for delivering liquid fuel from said nozzle body into a vehicle fuel tank fill pipe inclined at approximately 30° down from horizontal,    said nozzle spout having an inner wall surface defining a liquid flow passageway from said nozzle body to a spout tip, said wall surface having a first region extending to said spout tip and being disposed with generally uniform radius about an axis, a second region upstream from said first region and relatively closer to said nozzle body and being flared in a upstream direction, said second region of said inner wall surface being disposed at a first predetermined angle to said axis, and a third region upstream of said second region and relatively closer to the nozzle body and flared in an upstream direction, said third region of said inner wall surface being disposed at a second predetermined angle to said axis,    with said spout tip engaged in the vehicle fill pipe and said axis disposed in general alignment with a vehicle fill pipe axis, said inner wall surface in said first region, said second region, and said third region being disposed at effective angles below horizontal to encourage flow of liquid fuel toward said spout tip,    whereby, when said spout tip is removed from the vehicle fill pipe after a predetermined interval following cessation of flow of fuel from said nozzle body into said liquid flow passageway of said nozzle spout, dripping of residual liquid fuel from said spout tip is limited to a predetermined average number of drops of liquid fuel per fueling event.    
   
   
       17 . The fuel dispenser nozzle of  claim 16 , wherein the predetermined interval of time is approximately 10 seconds.  
   
   
       18 . The fuel dispenser nozzle of  claim 16  or  claim 17 , wherein the predetermined average number of drops of liquid fuel dripped per fueling event is about 3 drops or less.  
   
   
       19 . The fuel dispenser nozzle of  claim 16 , wherein said first predetermined angle is about 22° to said axis.  
   
   
       20 . The fuel dispenser nozzle of  claim 16  or  claim 17 , wherein said second predetermined angle is about 7°to said axis.  
   
   
       21 . A fuel dispenser nozzle comprising: 
 a nozzle body for delivering liquid fuel from a fuel dispenser towards a vehicle fuel tank, and    a nozzle spout associated with said nozzle body for delivering liquid fuel from said nozzle body into a vehicle fuel tank fill pipe inclined at approximately 30° down from horizontal,    said nozzle spout having an inner wall surface defining a liquid flow passageway between said nozzle body and a spout tip, said wall surface having a first region extending from said spout tip and being disposed with generally uniform radius about an axis, and a second region extending upstream from said first region to an aspirator ring and check valve assembly positioned in said liquid flow passageway relatively closer to but spaced along said liquid flow passageway from said nozzle body, said second region of said inner wall surface being flared in a upstream direction and disposed at a predetermined angle to said axis,    with said spout tip engaged in the vehicle fill pipe and said axis disposed in general alignment with a vehicle fill pipe axis, said inner wall surface in said first region and said second region of said nozzle spout being disposed at effective angles below horizontal to encourage flow of liquid fuel toward said spout tip,    whereby, when said spout tip is removed from the vehicle fill pipe after a predetermined interval following cessation of flow of fuel from said nozzle body into said liquid flow passageway of said nozzle spout, dripping of residual liquid fuel from said spout tip is limited to a predetermined average number of drops of liquid fuel per fueling event.    
   
   
       22 . The liquid fuel dispenser nozzle of  claim 21 , wherein, following cessation of flow of fuel from said nozzle body into said liquid flow passageway of said nozzle spout, said aspirator ring and check valve assembly seals an upstream portion of said liquid flow passageway, between said aspirator ring and check valve assembly and said nozzle body, to arrest leakage of residual fuel from the upstream portion into said first region and said second region of said liquid flow passageway downstream of the aspirator ring and check valve assembly for dripping from said spout tip.  
   
   
       23 . The fuel dispenser nozzle of  claim 21 , wherein the predetermined interval of time is approximately 10 seconds.  
   
   
       24 . The fuel dispenser nozzle of  claim 21  or  claim 23 , wherein the predetermined average number of drops of liquid fuel dripped per fueling event is about 3 drops or less.