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:
May. 16, 2017
Filed:
Dec. 18, 2012
Doosan Infracore Co., Ltd., Incheon, KR;
Won Sun Sohn, Seoul, KR;
Doosan Infracore Co., Ltd., Incheon, KR;
Abstract
The present disclosure relates to a boom cylinder control circuit for a construction machine, and includes: a boom cylinder which has an ascending-side chamber and a descending-side chamber; a boom control unit which provides a working fluid to the boom cylinder; a boom operation part which is operated to drive the boom cylinder by providing a pilot working fluid to the boom control unit; a first floating valve which allows the descending-side chamber and the ascending-side chamber to selectively communicate with or be shut off from a first drain line; a second floating valve which is additionally provided in a flow path between the descending-side chamber, which is connected with the first drain line via the first floating valve, and the first drain line, allows the descending-side chamber to communicate with the first drain line, or shut off discharge of the working fluid from the descending-side chamber to the first drain line, and allows of a reverse flow; and a floating selection operation part which provides an operation signal so that the first floating valve and the second floating valve are switched in a direction in which the first floating valve and the second floating valve are communicated or shut off.