The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 11, 2009
Filed:
Jun. 10, 2005
Method for the production of wear-resistant sides for a keystone ring for internal combustion engine
Kurt Maier, Leonberg, DE;
Jose Manoel Martins Leites, Stuttgart, DE;
Nuno Machado, Coimbra, PT;
Mahle GmbH, Stuttgart, DE;
Abstract
A method for the production of wear-resistant edges for a keystone ring for internal combustion engines, involves forming a rectangular ring from a steel strip with a rectangular cross-section, grinding the ring edges and the outer circumferential faces to give the required profile and brushing the inner circumferential face, grinding the upper and lower ring edge to form the keystone ring, complete nitriding of the piston ring surface by a gas-nitriding process (GNS) to form a nitride layer, profiling the nitrided piston ring by grinding and lapping without machining the nitrided edges of the piston ring, stacking the piston rings on the parallel faces, coating the outer circumferential faces of the piston rings with a wearing layer, and grinding the nitrided layer of the faces in the stacked state such that at most a quarter of the total thickness of the nitrided layer is removed.