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:
Mar. 27, 2018
Filed:
Jun. 29, 2015
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo, JP;
Abstract
A hydraulic system for construction machinery is capable of suppressing irregularity in the operation of the front structure not intended by the operator, and includes a regeneration motor adapted to be driven by return fluid from a bottom port of a boom cylinder; a regeneration electric motor converting rotary power into electric energy; return fluid control valves controlling the flow of the return fluid according to a pilot pressure related to an operation of a boom control lever; and a malfunction prevention device adapted to be activated by pressure fluctuation caused by malfunction of a solenoid valve for the return fluid control valve that interrupts the delivery of a pilot secondary pressure from the solenoid valve to the corresponding return fluid control valve.