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. 20, 2002
Filed:
Dec. 14, 1999
Seung Chel Choi, Koyang, KR;
LG Otis Elevator Company, Seoul, KR;
Abstract
A hydraulic elevator system of an inverter control method directly controlling a flow amount of a pressed oil discharged from a hydraulic pump by a speed control of a motor driving the hydraulic pump, which can improve energy efficiency and stability. The hydraulic elevator system includes a reverse check valve connected between a hydraulic cylinder operated by the pressed oil to lift/lower an elevator car and a hydraulic pump driven to discharge the pressed oil, opened to pass the pressed oil by the pressure of the discharged pressed oil in a driving of the hydraulic pump, and closed to prevent the pressed oil from being reversed by using a pilot pressed oil of the hydraulic cylinder as a power source in a stopping of the hydraulic pump; and a pilot hydraulic cylinder operated by the pilot pressed oil from the hydraulic cylinder in order to apply an additional close force to the reverse check valve in the lifting/lowering or emergency stopping of the elevator car.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile