US Patent 7543715 Vehicle fuel cap with axial longitudinal grooves in casing body

A vehicle fuel cap comprises a casing body for opening/closing a filler opening of a filler neck communicating with a fuel tank; and a lid that is equipped at an upper portion of the casing body and is formed of a conductive material, and the vehicle fuel cap forms a discharge portion in the lid for discharging static charge in the lid to the filler neck, wherein the discharge portion comprises a projection form provided on an inner peripheral face of the lid opposite to an outer peripheral edge of the filler opening, and on the inner peripheral face a longitudinal groove is formed at both sides of the discharge portion and along an axial direction of the casing body.