Height adjusting device
US5115723A · kind A · utility
Inventor
Key dates
| Filing date | Apr 30, 1991 |
| Grant date | May 26, 1992 |
| Priority date | — |
| Expiry date | Apr 30, 2011 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA47C3/30
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
A height adjusting device includes an outer cylinder, an inner cylinder disposed inside the outer cylinder, a fluid reservoir confined by the inner cylinder, and a fluid receiving space formed between the inner and outer cylinders. Fluid flows from the fluid reservoir to the fluid receiving space to retract the height adjusting device. A piston is provided between the inner and outer cylinders and is biased by a spring member to force fluid in the fluid receiving space to flow back into the fluid reservoir, causing expansion of the height adjusting device. The height adjusting device further includes a flexible fluid resisting ring that prevents untimely expansion of the height adjusting device by hindering fluid flow from the fluid receiving space into the fluid reservoir, which fluid flow is caused by the expanding force of the spring member.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.