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:
Nov. 28, 2000
Filed:
Dec. 20, 1999
Hisatoshi Hirota, Tokyo, JP;
Katsumi Koyama, Tokyo, JP;
TGK Co. Ltd., Tokyo, JP;
Abstract
In a four-way directional control valve of simplified construction and reduced manufacturing costs, first and second hollow cylindrical valve elements are arranged coaxially. Adjacent to opposite ends of the valve elements, first and second valve seats and first and second valve closure elements are provided. First and second pressure-regulating chambers are arranged between separator walls of the valve elements and first and second partition walls associated to the first and second valve seats. A pilot valve can be switched between switching positions for introducing high-pressure fluid originating from a first pipe into the first or second pressure-regulating chamber via a common high-pressure passage, a high pressure introducing hole and two pilot holes, respectively, associated to the pressure-regulating chambers. The control valve can be switched into a state where the first pipe communicates with the fourth and the second pipe communicates with the third pipe and to another state where the first pipe communicates with the third pipe and the second pipe communicates with the fourth pipe.