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:
Sep. 14, 1999
Filed:
Jul. 10, 1997
Applicant:
Inventor:
D Li Anatoli, Changwon, KR;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F15B / ; F15B / ;
U.S. Cl.
CPC ...
91450 ; 91457 ;
Abstract
A hydraulic system for working cylinders of construction equipment is disclosed. The system allows oil to be smoothly drained from a chamber of a working cylinder into an oil tank through a first passage or/and a second passage without being resisted during an operation of the cylinder. The system thus effectively and smoothly moves the working cylinder while improving operational efficiency and operational speed of the cylinder. When the system is used with a boom cylinder of a power excavator, the system effectively performs a boom-up or boom-down action without losing pressure.