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. 02, 2004
Filed:
Feb. 04, 2003
Hisatoshi Hirota, Tokyo, JP;
Katsumi Koyama, Tokyo, JP;
TGK Co., Inc., Tokyo, JP;
Abstract
A four-way switching valve includes a first three-way switching valve having a valve element for connecting a port B to a port A, or to a port D via a sleeve, in a switching manner; a second three-way switching valve having a valve element for connecting a port C to the port A, or to the port D, in a switching manner; and a piston for actuating these three-way switching valves. The three-way valves and piston are coaxially arranged within a hollow cylindrical body. A three-way solenoid valve introduces high pressure into a pressure chamber on the upper side of the piston to actuate the valve elements held on the sleeve downward, while the upward actuation is effected with a driving force produced by reducing the pressure in the pressure chamber and configuring guides to have a larger pressure-receiving area than that of a guide.