Selectively compressed expanded graphite gasket and method of making same
AssigneeFel-Pro Incorporated
InventorsRobert F. Locacius, Terence Zelenka
Life of this patent
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Abstract
A laminated expanded graphite gasket, such as an automotive head gasket, comprising a core and compressed expanded graphite facings and defining clear-through openings. A thin metallic layer is positioned on the graphite facing over less than 75% of the area of the facing for at least partial embeddment therein to enhance sealing stress in the covered portions, to improve impingment resistance of the gasket, and to improve other properties of expanded graphite gaskets.
Claims23
A laminated, selectively compressed, expanded graphite gasket assembly comprising:
- a thin self-supporting core having a pair of main faces and generally coextensive compressed expanded graphite facings of generally uniform thickness, one laminated to each main face, said gasket assembly defining at least one opening therethrough,
- a flat protective thin metallic layer at least partially embedded in at least one of said facing and covering portions of said facing which are less than 75% of the surface area of said facing, whereby the density of said graphite facing in the covered portions is greater than the density outside the covered portions and the sealing stress of said gasket assembly in use is greater in the covered portions than outside the covered portions.
A gasket assembly comprising:
- an expansive, thin self-supporting core defining a pair of main faces, and a compressed expanded graphite facing laminated to at least one of said main faces to provide a main gasket body,
- at least two openings defined by said main gasket body.
- a flat thin protective layer covering portions of said facing comprising less than 75% of the surface area of said expanded graphite facing and surrounding at least two openings defined by said main body,
- said thin protective layer being at least partially embedded in said facing and providing a density in the covered portions of said graphite facing which is greater than the density outside the covered portions of said facing.
A method of forming a graphite faced gasket having zones of different facing densities comprising the steps of
- forming a laminate comprising a thin self-supporting core having a pair of main faces and a generally coextensive compressed expanded graphite facing of generally uniform thickness laminated to at least one main face,
- providing at least one opening therethrough,
- providing a thin, generally flat protective metallic layer on the surface of at least one facing to cover portions of said facing over less than 75% of the surface area of said facing,
- and embedding said layer in said facing to reduce the thickness of the facing in the zone of said layer whereby the density of the graphite facing in the covered portions is greater than outside the covered portions and the sealing stress of the gasket assembly in use is greater in the covered portions than outside the covered portions.
Dependencies are inferred from the claim text.