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. 07, 1992
Filed:
Mar. 11, 1991
Applicant:
Inventors:
Yoshio Kojima, Hitachi, JP;
Tsutomu Okusawa, Hitachi, JP;
Kuniyoshi Tsubouchi, Mito, JP;
Yoichi Yoshinaga, Mito, JP;
Yusuke Takagi, Yokohama, JP;
Kenji Mitani, Yokohama, JP;
Nobuo Hamano, Tokyo, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F17D / ;
U.S. Cl.
CPC ...
137 13 ; 137828 ;
Abstract
Method of opening and closing a fluid passage comprises the steps of freezing fluid in the fluid passage by first cooling the fluid to a temperature below the freezing point of the fluid to close the fluid passage and after the fluid passage is closed, raising the temperature of the fluid close (or just below) to the freezing point of the fluid, whereby the fluid passage is maintained in a closed state with a small power supply and the responsiveness in opening the fluid passage is enhanced.