A Study on Improvement of Constant Repulsive Force Characteristic

The objective of this study is to improve the spring-link mechanism that generates constant repulsive force at an arbitrary position in the compression and the decompression processes of a stroke. This spring-link mechanism, constant-repulsive-force spring-link mechanism, is able to be useful in various fields. For instance, recently with the increase of the aged, quantity of care that needs a burden of a caretaker increases rapidly. If the stroke of this mechanism can be improved, the quantity of care may decrease. In this study, the combination of coil springs and mechanical linkages, X-link mechanism, is employed to realize such a characteristic. The characteristic that the repulsive force is always constant can be obtained by the combination of two kinds of characteristics : positive and negative spring constants. The stroke of this mechanism can be improved by using the superposition of some X-link mechanisms. This paper presents the improvement of constant-repulsive-force spring-link mechanism.