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:
Jan. 04, 1994
Filed:
Apr. 16, 1993
Klaus Rubner, Lauf, DE;
Hoechst CeramTec Aktiengesellschaft, Selb, DE;
Abstract
A valve disk of silicon-infiltrated silicon carbide material for control elements for regulating liquid flows is suitable in particular for service-water mixer valves. The silicon carbide material contains 70 to 90% by weight of silicon carbide and 8 to 30% by weight of silicon with a content of most 0.2%, by weight of free carbon and contains at most 0.1% by volume of closed pores. The valve disk has a functional surface having the optical appearance in the form of isolated islands of bearing surfaces surrounded by a level lying lever with respect to the isolated islands, the functional surface having the following microtopographical characteristics over its entire region: R.sub.a : 0.02 to 0.80 .mu.m, preferably 0.15 to 0.40 .mu.m; R.sub.t : 0.50 to 6.00 .mu.m,; R.sub.z : 0.20 to 100 .mu.m: flatness: 0.0002 to 0.01 mm; t.sub.pi : 40 to 80% (at 0.3 .mu.m cut depth); t.sub.pa : 10 to 60% (at 0.3 .mu.m cut depth). The invention also relates to a process for producing the valve disk.