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. 06, 2010
Filed:
Jun. 13, 2008
Tomoo Harada, Anjo, JP;
Tomoo Harada, Anjo, JP;
Advics Co., Ltd., Kariya, Aichi-Pref., JP;
Abstract
A piston pump includes a first piston pump including a first piston and a first pump chamber, a second piston pump including a second piston and a second pump chamber, the second piston operating to follow the first piston, a pressure release passage formed in communication with the second pump chamber, and a relief valve provided at the pressure release passage and defining an upper limit discharge pressure of the second piston pump. When a discharge pressure of the second piston pump is equal to or smaller than the upper limit, a discharge fluid of the second piston pump is added to that of the first piston pump so as to flow into an outlet port. When the discharge pressure exceeds the upper limit, the discharge fluid is released to the pressure release passage and the discharge fluid of the first piston pump only flows to the outlet port.