Cylinder head gasket

A cylinder head gasket for providing a seal between a cylinder block and a cylinder head, the cylinder block defining a cylinder bore, the cylinder head gasket composed of a composite base plate, comprising a core material plate and a compound layer formed on the front and back surfaces of said core material plate, said compound layer being formed by coating compound materials containing a rubber and fiber material, said cylinder head gasket so composed, comprising:

• an annular groove which is formed in the compound layer associated with said cylinder bore, said annular groove being formed by pressing a corresponding region of said compound layer around said associated the cylinder bore, and defining thereby a bottom surface and an outer top surface;
• an annular step groove, associated with said annular groove, that forms a shoulder in said compound layer, said annular step groove on each side defining a top vertical wall which extends from the outer top surface, a horizontal wall and a bottom vertical wall which extends to said bottom surface;
• said bottom surface and said bottom vertical walls forming a chamber;
• and
• a seal member formed by inserting rubber material into said chamber, said seal member having a bead portion projecting above the top outer surface of said compound layer and a base portion which defines a top surface substantially coplanar with said horizontal wall.