Single layer head gasket with integral stopper and method of making the same
AssigneeDana Corporation
InventorsGerald Emil Kashmerick, Thomas P. Plunkett
Life of this patent
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Abstract
A gasket for use in an internal combustion engine is disclosed which includes a sealing element formed by an extrusion and ironing process in combination with a folding operation. The gasket has a plate that includes a body portion, a flange portion and an aperture. The thickness of the flange portion is reduced to less than that of the body portion by the extrusion and ironing process. The flange portion is then folded back onto a surface of the plate in facing relation to form a stopper seal to act as a primary seal. Optional embossments may then be formed radially and outwardly of the stopper seal so as to form a secondary seal.
Claims21
A gasket, comprising:
- a metallic plate having a body portion, a flange portion and an aperture;
- said flange portion having a top and a bottom surface, said bottom surface including an offset portion, said flange having a predetermined thickness that is less than a predetermined thickness of said body portion;
- and
- a stopper seal formed by an end of said flange portion being folded over about a fold line and onto a surface of said body portion such that one of said top and bottom surfaces of said flange portion is abutting and in facing relation to said surface of said body portion, an edge of said stopper seal defining a remnant of said fold line and the inner periphery for said aperture such that said stopper seal acts as a primary seal to prevent undesirable escaping of gases and fluids from said aperture.
A method of forming a single layer gasket with an integral stopper seal, comprising the steps of:
- providing a plate having a substantially uniform first thickness, said plate including a body portion and a flange portion, said flange portion encircling a perimeter of an aperture wherein said aperture has a first diameter, said flange portion being slightly offset from said body portion to form an offset portion and including an upper surface that is sloped slightly upwardly away from an upper surface of said body portion to form a tapered thickness portion;
- positioning said plate in a die assembly such that said aperture is spaced away from said die assembly;
- positioning a tapered extrusion punch press adjacent to said assembly and above said flange portion and said aperture of said plate, said tapered extrusion punch press being spaced a distance away from said inclined die assembly so as to provide a gap therebetween;
- operating said tapered extrusion punch press in a downward direction to extend through said aperture and contact said flange portion, thereby bending said flange portion about a fold line and disposing said flange portion within said gap such that said flange portion is extruded and ironed to a predetermined uniform seal thickness, said seal thickness being less than said first thickness of said plate;
- and
- folding said flange portion about said fold line onto a surface of said body portion such that said flange portion is abutting and in facing relation to said surface of said body portion so as to form a stopper seal, an edge of said stopper seal defining a remnant of said fold line and an inner periphery of said aperture, wherein said extrusion and ironing step enlarges said aperture so as to have a second diameter that is greater than said first diameter.
Dependencies are inferred from the claim text.