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. 03, 2018
Filed:
Oct. 10, 2014
Kawasaki Jukogyo Kabushiki Kaisha, Kobe-shi, Hyogo, JP;
KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe-shi, JP;
Abstract
A hydraulic excavator drive system includes: a first hydraulic pump and a second hydraulic pump, whose respective tilting angles are controllable independently of each other; an arm main control valve and an arm auxiliary control valve each for controlling supply of hydraulic oil to an arm cylinder; and a boom main control valve and a boom auxiliary control valve each for controlling supply of the hydraulic oil to a boom cylinder. An arm operation valve outputs a pilot pressure to the arm main control valve. A boom operation valve outputs a pilot pressure to the boom main control valve. A pair of arm-side regulating valves outputs no pilot pressure to the arm auxiliary control valve and a boom-side regulating valve outputs no pilot pressure to the boom auxiliary control valve when an arm crowding operation and a boom raising operation are performed concurrently.