Patent ID: 7909337

Claim:
A gasket comprising: a pair of base plates stacked one over the other, in each of which combustion chamber holes are bored and a first bead is disposed surrounding each of the combustion chamber holes, wherein in each of said base plates, a flat part on said combustion chamber hole side relative to the position where said first bead is formed refers to a first flat part and a flat part away from said combustion chamber hole relative to said first bead refers to a second flat part; a doubling plate stacked between said pair of base plates and having at least one deformable second bead disposed surrounding each of the combustion chamber holes, the at least one deformable second bead having a curved shape and being positioned between the combustion chamber hole and the first bead, wherein the doubling plate and each of the pair of base plates have substantially a same thickness; and a shim plate stacked on the doubling plate and extending between a first end and a second end, wherein the first end of the shim plate is positioned proximate the second flat part, the shim plate extending to the combustion chamber hole, where the shim plate is folded back such that the second end is positioned between the second bead and the first bead along the first flat part.