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:
Dec. 01, 1998
Filed:
Aug. 27, 1996
Applicant:
Inventors:
Hideki Nakayoshi, Aichi-pref., JP;
Naoki Oogushi, Aichi-pref., JP;
Assignee:
Aisin Seiki Kabushiki Kaisha, Aichi-pref., JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B / ;
U.S. Cl.
CPC ...
417286 ; 417310 ; 417428 ;
Abstract
A tandem pump apparatus is featured having a main suction passage connected to a fluid source. The main suction passage branches into first and second suction passages which, in turn, feed into first and second pumps. Each pump discharges a portion of the fluid to a return passage that is fluidly connected to the suction port of each respective pump. In each return passage, a return control valve is disposed to control the amount of fluid returned to the suction port. The tandem pump featured in this invention exhibits increased efficiency and decreased noise.