| 摘要 |
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. In an automobile trunk installation, the assembly is installed with the spring in lateral disposition in the forward upper portion of the trunk, thus being effectively concealed. Alternative 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 characterisitcs of the spring shaft seal and the partition wall seal, enables compensation for leakage from the cylinder. Multiple force output provisions can be used in a substantially vertically disposed spring, filled with a predetermined quantity of oil, and used as a liquid-pneumatic shock absorber. A supplemental orifice type disc valve unit can be used in such a shock absorber, located near the closed end of the spring cylinder. |
