Plastic stand pipe support for load-bearing adjustable column
US5161786A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 15, 1991 |
| Grant date | Nov 10, 1992 |
| Priority date | — |
| Expiry date | May 15, 2011 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA47C3/30
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
A plastic stand pipe designed for application to furniture such as a chair, to replace a metal stand pipe supporting a gas fluid spring which allows a seat to be raised and lowered as desired. The plastic stand pipe is attached to the chair base, and encloses the fluid spring which supports the seat. The inventive design relies on the combination of a novel structural configuration of the stand pipe inner working parts which support the fluid spring cylinder and use of appropriate plastic engineering materials to achieve the result allowing for replacement of the metal stand pipe. The structural configuration features a plurality of ribs formed on the inner wall of a plastic tubular member, such that the ribs contact the fluid spring cylinder and provide circumferential support. The end of each rib is formed with a support projection which is flexible, and the plurality of support projections form a floating support ring allowing for some freedom in the fluid spring movement from side to side at its top end. The design of the interior ribs supplies the dual function of guiding the fluid spring with flexibility while providing sufficient rigidity to support loads placed on it. The p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.