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:
Feb. 05, 2013
Filed:
Sep. 19, 2008
Akinori Ishii, Ushiku, JP;
Akinori Ishii, Ushiku, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A dual arm hydraulic excavatorhas two front work devices A and B, provided on left and right sides of a front portion of an upper swing structureand swingable in a top-bottom direction of excavator. Front work devices A and B have arms, boomsand working devices. An average of angle θa of the armrelative to the boomand angle θb of the armrelative to the boomis defined as an average arm angle θc. A range of the average arm angle, in which the average arm angle θc is larger than a predetermined threshold value θc, is defined as an unstable range N. A range of the average arm angle, from an inner side of the unstable range and adjacent to the unstable range, is defined as a stable state limit range M.