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. 03, 1990
Filed:
Jul. 25, 1988
Akio Tomiyama, Hitachi, JP;
Osamu Yokomizo, Ibaraki, JP;
Yasuhiro Masuhara, Katsuta, JP;
Toshitsugu Nakao, Hitachi, JP;
Shin-ichi Kashiwai, Hitachi, JP;
Yoshishige Kawada, Hitachi, JP;
Hiromasa Hirakawa, Hitachi, JP;
Shigeto Murata, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A fuel assembly according to the present invention is formed in such a manner that the small diameter portion of an upper end plug of a fuel rod is inserted into a boss of an upper tie-plate. The upper end plug includes a small diameter portion and a large diameter portion which is disposed below the former. An expansion spring in disposed in the small diameter portion of the upper end plug. A cover member surrounding this expansion spring is disposed in the large diameter portion of the upper end plug, and extends upwardly. Since the cover member surrounds the expansion spring, pressure loss caused by the expansion spring can be reduced.