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:
Mar. 20, 1990
Filed:
Jul. 10, 1989
Hitachi, Ltd., Tokyo, JP;
Abstract
In a fluid control valve, a check valve is provided between the pump port and the first fluid chamber and allows the fluid to pass therethrough only in a direction from the pump port to the first fluid chamber, a down control valve is provided between the first fluid chamber and the second fluid chamber, an up control valve is provided between the first fluid chamber and the third fluid chamber, the fluid is allowed to flow from the pump port to the cylinder port through the check valve and through the down control valve when they are opened, and the fluid from the cylinder port to the tank port is allowed to flow through the down control valve, through the first fluid chamber and through the up control valve when they are opened. The fluid control valve can be obtained simple in structure and high in precision, and be allowed a reduction in cavitation and noise.