Pneumatic spring structure with dual output force and pressure decay compensation and method of operation
US4854554A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 20, 1988 |
| Grant date | Aug 8, 1989 |
| Priority date | — |
| Expiry date | Sep 20, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S277/91
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A transversely mounted, single pneumatic spring, and dual bell crank and idler link assembly providing a compact counterbalance for hinged closures such as automobile trunk lids. Pneumatic spring enhancements, e.g., a multi-output force feature and a pressure decay compensation feature may be incorporated in the spring unit to enhance opening of the lid and to improve life expectancy of the pneumatic spring by minimizing and effectively negating pressure loss due to leakage of gas past the shaft seal. Excess spring cylinder length can provide space or volume zones used for the enhancement features. Structure which provides a multiple output force for the pneumatic spring, utilizes positioning of the spring shaft end bushing and seal to vary the working volume by changing effective cross-section area of the piston shaft near the end of a compression stroke. The extra cylinder length enables a sealed partition wall to separate extra volume and the operative volume part of the cylinder. The extra volume is filled with a supply of gas under higher pressure than that of the spring operative gas pressure and, in conjunction with permeability characteristics of the spring shaft seal and t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.