Hydraulic elevator with an accumulator
US6957721B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 9, 2001 |
| Grant date | Oct 25, 2005 |
| Priority date | — |
| Expiry date | Jan 20, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B50/00
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A pump is situated between the hydraulic drive and the accumulator, this pump being driven by a motor and conveying hydraulic oil from the hydraulic drive to the accumulator and vice versa without the presence of control valves which influence the flow of hydraulic oil, such as proportionally pilot-operated valves. Since the pump is subjected to the pressure Pz in the cylinder line and the pressure Ps in the accumulator line, the motor of the pump only has to work against the differential pressure and in certain operating states, can even function as a generator and release electrical energy through a power output device controlling it. The speed of the car is controlled through the control of the motor alone by a control and regulation device, through the power output device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.