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:
Jun. 11, 1985
Filed:
Jan. 17, 1984
Applicant:
Inventors:
Ulf Dworak, Baltmannsweiler, DE;
Hans Olapinski, Aichwald, DE;
Dieter Fingerle, Hochdorf, DE;
Ulrich Krohn, Leonberg, DE;
Assignee:
Feldmuhle Aktiengesellschaft, Dusseldorf, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16J / ;
U.S. Cl.
CPC ...
277216 ; 277224 ; 277D / ;
Abstract
A piston ring (1) made of ceramic materials for an internal combustion engine comprising a body made by sintering of partially stabilized zirconium oxide (PSZ) which has a porosity <3% and, rolling surface (4) of the piston ring having a centerline average roughness R.sub.a of 0.03 to 0.1 .mu.m. Due to its homogeneous structure, the inventive piston ring avoids the problems of the ceramic/metal bond of known piston rings and, even under high thermal load, does not suffer from thermally induced destruction or welding of the piston ring groove.