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. 26, 2005
Filed:
Jun. 10, 2003
Katsumi Koyama, Tokyo, JP;
Katsumi Koyama, Tokyo, JP;
TGK Co., Ltd., Tokyo, JP;
Abstract
The object of the present invention is to provide a three-way switching valve having a valve mechanism compact in size, and capable of changing a flow of a high-pressure fluid, without internal leakage of the fluid. A compact pilot-operated three-way switching valve changes a flow of a fluid introduced into an inlet port such that the fluid is caused to flow into a first outlet port or a second outlet port. Pressures in pressure-regulating chambers above pistons are selectively guided into a passage by a pilot valve having a pilot valve element, plugs including respective valve seats, and a spring. The passage leads one of the pressures to the first outlet port or the second outlet port via a check valve having valve, and a valve element. The check valve causes a very small amount of fluid permitted to flow so as to keep main valves open and closed, respectively, to flow to the downstream side of an open one of the main valves, whereby internal leakage of fluid is prevented.