Soft-start, soft-return gas spring
US6390457B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Feb 14, 2001 |
| Grant date | May 21, 2002 |
| Priority date | — |
| Expiry date | Feb 14, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2205/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A gas spring includes an outer tube; a base plate; a head plate; an inner tube mounted to extend between the head plate and the base plate; a piston/rod assembly mounted to reciprocate vertically in the inner tube between a retracted, compressed position and an extended, rest position; a valve ring coaxially mounted around the rod to reciprocate between the main piston and head plate; a primary gas chamber; a relief chamber; seals for preventing fluid flow from the primary and relief chambers; a passageway providing communication between the primary gas chamber and relief chamber; and, valve apparatus for controlling fluid flow between the primary and relief chambers. The valve apparatus operates to open and close the fluid flow as a function of the position and direction of travel of the piston/rod assembly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.