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:
Jan. 08, 2013
Filed:
Feb. 12, 2009
Katsumi Yamashita, Aichi-ken, JP;
Shigeru Suzuki, Aichi-ken, JP;
Hironao Yokoi, Aichi-ken, JP;
Toshiro Fujii, Aichi-ken, JP;
Katsumi Yamashita, Aichi-ken, JP;
Shigeru Suzuki, Aichi-ken, JP;
Hironao Yokoi, Aichi-ken, JP;
Toshiro Fujii, Aichi-ken, JP;
Abstract
The variable displacement gear pump for a loading system in an industrial vehicle has main and sub gear pump portions, suction, discharge and bypass passages, and check and opening valves. The main gear pump portion has main drive and driven gears, and has suction and discharge side spaces. The sub gear pump portion has sub drive and driven gears, and has suction and discharge side spaces. The bypass passage returns hydraulic fluid in the discharge-side space of the sub gear pump portion to the suction passage. The check valve prevents hydraulic fluid in the discharge-side space of the main gear pump portion from flowing to that of the sub gear pump portion. The opening valve is used for opening and closing the bypass passage, and closes the bypass passage due to a pressure in a discharge conduit of the loading system increased by the load applied to the loading system.