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:
Jan. 28, 2003
Filed:
Nov. 05, 2001
Sead Veletovac, Dübendorf, CH;
Luigi Del Re, Zürich, CH;
Wittur AG, Wiedenzhausen, DE;
Abstract
A method for controlling a hydraulic elevator whose car can be displaced by a hydraulic drive mechanism by hydraulic oil fed through a cylinder line or evacuated from said hydraulic drive mechanism by a pump that cooperates with a first control valve unit and a second control valve unit, wherein the flow the hydraulic oil is controlled by a measuring device and operation of the elevator can be controlled and regulated by a control apparatus. The load of the elevator car is determined by a load pressure sensor detecting pressure P in the cylinder line and is controlled preferably in a constant manner by changing the control of the second control valve unit in such a way that movement of the elevator car can be controlled in a very precise manner. When the elevator car is descending, the dropping pressure P in the cylinder line is regulated by changing the first control valve unit in such a way that the descending movement of the elevator-cabin can also be controlled in a very precise manner.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile