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. 18, 1991
Filed:
Dec. 19, 1989
Masaaki Ohshima, Chofu, JP;
Akira Kobayashi, Chofu, JP;
Senji Atsumi, Kakamigahara, JP;
Hiromi Shimada, Nagoya, JP;
The Tokyo Electric Co., Tokyo, JP;
NGK Insulators, Ltd., Aichi, JP;
Abstract
A solid electrolyte tube for sodium sulfur cells, having an outer surface of a roughness defined by an arithmetical mean deviation of the profile (R.sub.a) of not exceeding 2.0 .mu.m and a maximum height of the profile (R.sub.max) of not exceeding 15 .mu.m, is produced by leveling the outer surface of the solid electrolyte tube in a state of green body, bisque fired and calcined body, or fired body, by means of a finishing apparatus such as a centerless grinding machine, external cylindrical grinding machine, lathe, or the like. The solid electrolyte tube having a smooth and even surface can be prevented from crack formation due to local concentration of Na ion, S, sodium polysulfide and thermal stress thereon, so that it can improve durability and reliability.