Patent ID: 7644740

Claim:
An assembly for covering a filler neck in a fuel system, comprising: a body portion having an opening that corresponds to an opening in the filler neck; a protective door coupled to the body portion, wherein the door is slidable between an open position that exposes the opening in the body portion and a closed position that covers the opening in the body portion; and a pair of spaced body protrusions disposed on the body portion at a first distance from each other; and a pair of spaced door protrusions disposed on the door at a second distance from each other, wherein the body protrusions and the door protrusions are spaced at a distance from each other to accommodate a nozzle of a first fuel type having a first nozzle diameter and to prevent accommodation of a nozzle of a second fuel type having a second nozzle diameter, wherein the first fuel type is gasoline and the second fuel type is diesel fuel, and wherein: the first distance on the body portion is larger than the first nozzle diameter and smaller than the second nozzle diameter to prevent the diesel fuel nozzle from passing between the body protrusions; and the second distance on the door is equal to or smaller than the first nozzle diameter to form a ledge that engages the gasoline nozzle to allow the gasoline nozzle to slide the door open.