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:
Apr. 14, 1992
Filed:
Jun. 05, 1991
Hidenobu Misawa, Nagoya, JP;
Satoru Yamada, Nagoya, JP;
NGK Insulators, Ltd., , JP;
Abstract
A one-end closed ceramic double tube has an integral structure comprising: a one-end closed outer cylinder; an inner cylinder extending concentrically with said outer cylinder; and at least one support portion extending laterally to bridge said outer and inner cylinders and longitudinally from near the closed end at least up to the open end of said outer cylinder, wherein the ratio of a total thickness of the support portions in contact with the inner circumference of the outer cylinder to the inner circumference of the outer cylinder at cross section is most 25%, and preferably, the outside diameter ratio of the outer cylinder to the inner cylinder is at most 3.3. An air passage formed on the inner cylinder near the closed end side of the tube communicates between the inner passageway inside the inner cylinder and the outer passageway defined by the inner and outer cylinders. This double tube has high reliability and sufficient mechanical strength and can be suitably used as filters, heat exchangers, concentrators and as supporting tubes for fuel cells. This double tube is manufactured by means of extrusion molding.