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:
Jul. 16, 1991
Filed:
Sep. 07, 1988
Applicant:
Inventors:
Ulf Dworak, Baltmannsweiler, DE;
Dieter Fingerle, Hochdorf, DE;
Kilian Friederich, Plochingen, DE;
Hans Olapinski, Aichwald, DE;
Assignee:
Feldmuhle Aktiengesellschaft, Duesseldorf, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C25F / ;
U.S. Cl.
CPC ...
156625 ; 156667 ; 252 792 ;
Abstract
Combinations of frictional and sealing elements made from hard substances, such as sintered aluminum oxide, are ground and lapped at their surfaces of engagement. At least one surface has at least some micro-blurred areas. The micro-blurring is produced by chemical etching. Phosphoric acid can be used as the chemical etching, and in thermal etching, the etching temperature is between 1400.degree. and 1560.degree. C.