Pneumatic spring counterbalance having improved damping structure
US4570912A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 8, 1982 |
| Grant date | Feb 18, 1986 |
| Priority date | — |
| Expiry date | Oct 8, 2002 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16F9/49
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A pneumatic spring counterbalance extensible link including a closed end cylinder with an end connector, a piston and rod assembly within the cylinder and maintained therein by the crimped over end portion of the cylinder retaining a rod bushing and rod to cylinder seal assembly. The cylinder is pressurized preferably prior to assembly of the bushing and seal assembly into the cylinder. The piston assembly includes an effective check valve and orifice by-pass structure for metered gas flow past the piston in one direction and free flow past the piston in the other direction of piston movement. A small predetermined amount of oil is contained in the cylinder and provides lubrication for the seals and piston and provides a damping effect at the end of the extension stroke. A standpipe sleeve is secured on the piston extending toward the seal assembly around the piston rod and controls disposition of the oil to assure damping at the end of the extension stroke. A piston and piston ring structure enhance reliability of control of the oil flow, by providing a peripheral piston to cylinder seal and assures that fluid only passes across the piston via the check valve and orifice by-pass s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.