Hydraulic chair lift mechanism
US4593951A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 5, 1984 |
| Grant date | Jun 10, 1986 |
| Priority date | — |
| Expiry date | Nov 5, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S297/03
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
A hydraulic lifting mechanism for an article of furniture comprising a pair of sealed chambers interconnected with a hollow conduit and containing hydraulic fluid. One of the chambers is expandable and comprises flexible walls in the form of a rolling diaphragm. The second chamber contains a pressurized gas in addition to a hydraulic fluid. The expandable chamber is located in the supporting base of the article of furniture. A two speed valve is included in the interconnecting conduit for allowing fluid transfer between the chambers at a first rate in one direction and at a second rate in the other direction. As fluid is transferred to the expandable chamber, a support column will be forced upwardly by the expanding chamber at a fast rate and when the fluid transfers from the expandable chamber to the second chamber the support column will move downwardly at a second rate of speed slower than the first rate. The second chamber and the control valve can be located remotely from the base of the article of furniture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.