Patent ID: 7690527

Claim:
A cap and gasket for creating a seal with a sealing surface, the cap having a threaded cylindrical portion for mating with a corresponding threaded aperture and a top portion extending radially beyond the cylindrical portion and having an underside opposing the sealing surface, said gasket having a zone of contact from which said gasket is attached and extends from the underside of the cap, the gasket having a profile including a pair of winged portions extending away from the zone of contact, said winged portions forming a sealing width greater than the width of the zone of contact, the winged portions forming a concave surface spaced outwardly from the zone of contact for creating a seal against the sealing surface, the winged portions being asymmetrical with one of said winged portions forming an angle with the underside which is different from an angle formed by the other winged portion, the gasket being positioned so as not to contact the cylindrical portion of the cap.