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:
Aug. 14, 2018
Filed:
Jul. 17, 2015
Kobelco Construction Machinery Co., Ltd., Hiroshima-shi, JP;
Hidenori Tanaka, Hiroshima, JP;
Kensuke Ishikura, Hiroshima, JP;
Koji Ueda, Hiroshima, JP;
Takaaki Izuka, Hiroshima, JP;
KOBELCO CONSTRUCTION MACHINERY CO., LTD., Hiroshima-shi, JP;
Abstract
A hydraulic excavator includes control valves connected to a head-side chamber of a boom cylinder, an operating unit configured to switch the control valves, lock valves each provided between the head-side chamber and each of the control valves, and an operation control unit that controls the operation of the lock valves. The lock valves each have a valve element that is configured to move between a locking position at which the discharge of hydraulic oil from the head-side chamber is restricted and an unlocking position at which the discharge of the hydraulic oil from the head-side chamber is allowed. The operation control unit controls the operation of the lock valves so that the valve elements move from the locking position to the unlocking position at different points in time when the operating unit is operated.