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:
May. 06, 2008
Filed:
Mar. 15, 2005
Junichi Motojima, Gunma, JP;
Masaaki Iijima, Gunma, JP;
Junichi Motojima, Gunma, JP;
Masaaki Iijima, Gunma, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A check valve includes a housing formed with a valve hole through which fluid flows, a valve seat formed on the peripheral wall of the valve hole, a valve element disposed in the valve hole to be movable between a valve closed position where the valve element makes close contact with the valve seat to close the valve hole and a valve open position where the valve element moves away from the valve seat in the downstream direction to open the valve hole, a coil spring for biasing the valve element toward the valve closed position wherein the coil spring is larger in outer diameter than valve element, and a pressure acting portion provided to the coil spring so as to undergo the pressure of fluid.