Axially adjustable pneumatic spring
US4318536A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 23, 1980 |
| Grant date | Mar 9, 1982 |
| Priority date | — |
| Expiry date | Jan 23, 2000 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16F9/0245
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A pneumatic spring for use, for example, as a lifting device or support strut for a chair or the like with provision for the adjustment of axial extent. The pneumatic spring is substantially composed of a telescoping cylinder-piston assembly containing a gas and/or fluid under compression. A releasable valve assembly permits the relative position of the piston with respect to the housing to be adjusted arbitrarily. In order to provide for a terminal spring stiffening in the position of near full insertion of the piston rod, the invention provides that a pin extending from the main piston enters a central volume which is thereby sealed off from the remainder of the internal volume. Accordingly, the gas in the remaining available volume is compressed more highly and exerts an increased opposing force on the primary piston during its final insertion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.