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:
Jun. 09, 2020
Filed:
Feb. 20, 2018
Hitachi Construction Machinery Co., Ltd., Taito-ku, Tokyo, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
In a construction machine with a hydraulic pilot type hydraulic control device, occurrence of jerking is prevented. A hydraulic excavatorhaving hydraulic pumpsL andR, travel motorsL andR, traveling operating leversL andR, a pilot pump, hydraulic pilot valvesLa,Lb,Ra, andRb, and directional control valvesL andR includes: changeover switchesL andR which change the operating mode of the traveling operating leversL andR; pilot pressure adjusting devicesL andR which adjust the pilot pressure applied to the directional control valvesL andR; and pilot pressure sensorsLa,Lb,Ra, andRb. The pilot pressure adjusting devices apply the pilot pressure at the time when the operating mode of the traveling operating leversL andR is changed to a control mode, to the directional control valvesL andR.