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. 11, 2003
Filed:
Apr. 16, 2001
Applicant:
Inventors:
Kenzo Oba, Tochigi, JP;
Katsuyuki Yoshida, Tochigi, JP;
Assignee:
Showa Corporation, , JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B 4/900 ;
U.S. Cl.
CPC ...
F04B 4/900 ;
Abstract
In a variable displacement pump, a relief valve is constituted by a pilot drive type relief valve obtained by adding a pilot valve to a main valve, a fluid pressure in a downstream side of a metering orifice provided in a pump discharge side passage is applied to the pilot valve, and the main valve is capable of opening and closing a downstream side passage of the metering orifice with respect to a drain passage.