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. 14, 2003
Filed:
Nov. 28, 2001
Josef Zürcher, Neuheim, CH;
Daniel Moser, Menzingen, CH;
Bucher Hydraulics AG, Neuheim, CH;
Abstract
A hydraulic elevator with a pressure accumulator acting as a counterweight, includes a first pump for conveying hydraulic oil through a pump line, at least one valve unit, and a cylinder line to and from a hydraulic drive for a car, a second pump for conveying hydraulic oil by way of a solenoid valve from and to the pressure accumulator, which hydraulic oil can be supplied to and withdrawn from a tank. The two pumps are connected rigidly to each other and can be driven by an electric motor, the speed of which can be regulated. A single valve unit is installed between the first pump and the hydraulic drive, the valve unit being a relay-controllable valve and a first nonreturn valve connected in parallel to the relay-controllable valve. A control/automatic regulation unit is provided, and in order to control the speed of the car, acts on a power regulating unit for the electric motor, on the solenoid valve, and also, during descents, on the relay-controllable valve. A process for control and regulation of the operation of the elevator is provided, the elevator and its operation being such as to reduce the amount of electric energy required to drive the motor and thus to operate the hydraulic elevator.