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:
Nov. 14, 2006
Filed:
Nov. 07, 2002
Hugo Birbaumer, Neuheim, CH;
Richard Von Holzen, Menzingen, CH;
Hugo Birbaumer, Neuheim, CH;
Richard von Holzen, Menzingen, CH;
Bucher Hydraulics AG, Neuheim, CH;
Abstract
A hydraulic elevator with a pressure accumulator includes a pump fir conveying hydraulic oil between the pressure accumulator and a hydraulic drive, such that the direction of rotation of the pump can be changed. An electrically controlled cylinder line stop valve is installed on one side of the pump, and an electrically controlled accumulator line stop valve is installed on the other side of the pump. Both valves are ON-OFF valves. To prevent sudden disruptive pressure changes when the valves are opened before the start of travel of the car, the pressure in the section of the line between the pump and the cylinder line stop valve and in the section of the line between the pump and the accumulator line stop valve can be varied such that, when the car is at a standstill, the pressure differences are largely eliminated before the valves are opened.