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. 08, 2001
Filed:
Sep. 03, 1998
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
When an arm end exceeds a boundary line K,and enters a slowdown area R,a proportional solenoid pressure reducing valve,is operated to reduce a pilot pressure for slowing down a first boom cylinder,A, thereby slowing down an arm end speed. When the arm end exceeds a boundary line K,and enters a restoration area R,a restoration gain is calculated in control gain block,depending on an intrusion amount by which the arm end enters the restoration area, while a feedback gain is calculated depending on an arm end speed at that time on the basis of functions,and,In accordance with these gains, a second boom,is automatically dumped depending on the intrusion amount of the arm end into the restoration area and the arm end speed at that time so that the arm end is moved for return to the slowdown area. As a result, such work as requiring a work front to be moved toward the operator is continuously smoothly performed and working efficiency is improved.