Cylinder head gasket for internal combustion engine

Claim 1

A cylinder head gasket for an internal combustion engine comprising: a metal central plate formed with a row of openings for cylinders of said engine and a plurality of passages for liquids circulated in said engine; respective elastomeric beads surrounding said passages and forming liquid seals, said liquid seals being disposed symmetrically on opposite sides of said plate and being affixed thereto; and respective refractory annuluses lining each of said openings and defining gas seals for said openings, said annuluses being composed entirely of metal, said plate being set back from said seals at said opening, each of said annuluses comprising: a pair of ribbed sheet metal members having said plate received between them and having respective inner ribbed perimeters extending inwardly beyond said plate into each of said openings, the ribs of said perimeters being symmetrical with respect to a plane of said plate, one of said ribbed members being coplanar with a surface of said plate, the other of said ribbed members having its perimeter offset toward said one of said ribbed members, a first sheet metal cover member having a C-section portion reaching over said ribbed members and between said ribbed members while overlying said other ribbed member, and a second sheet metal cover member having a C-section portion reaching around said inner perimeters and said first cover member while underlying said one of said ribbed members.