Fuel tank neck seal arrangement

Abstract

A fuel tank has a neck into which a flange of a level sender unit is to be sealed. A seal gasket surrounds the neck and is received between converging seal surfaces, one on the neck and the other on the flange, and the outside of the neck. A flange nut is provided to clamp the flange to the neck, thus compressing the gasket between the seal surfaces to effect a seal.

I claim:  
     
         1 . A fuel tank neck seal arrangement comprising: 
 an annular flange and neck and wherein said flange is to be sealed against the neck;    the arrangement comprising an annular seal gasket surrounding said neck converging seal surfaces on said flange and said neck on opposite sides of said gasket so that converging movement of said flange and said neck will compress said clamp and the gasket between the flange and the neck, compressing the gasket to effect a seal.    
     
     
         2 . An arrangement as claimed in  claim 1 , wherein the seal surface on the neck is moulded integrally with the tank.  
     
     
         3 . An arrangement as claimed in  claim 1 , wherein the seal surface on the flange is integral with the flange.  
     
     
         4 . An arrangement as claimed in  claim 1 , wherein the seal surfaces have an included angle of between 5° and 25°.  
     
     
         5 . An arrangement as claimed in  claim 1 , wherein the seal gasket has a D-shaped cross-section.  
     
     
         6 . An arrangement as claimed in  claim 5 , wherein the flat part of the D-shaped cross-section fits against the neck between the converging flange and neck.  
     
     
         7 . An arrangement as claimed in  claim 6 , wherein the seal gasket is constrained on three sides and unconstrained on a fourth side.  
     
     
         8 . An arrangement as claimed in  claim 1 , wherein a threaded nut engages an external thread on the neck to enable the nut to cause the gasket to be compressed.  
     
     
         9 . An arrangement as claimed in  claim 8 , wherein the external thread on the neck is below the converging seal surface on the neck.