Spring assembly and power transmission device using the same

摘要

A spring assembly comprising an inner ring spring and an outer ring spring suitable for use in a safety device for an automobile power window is provided. The inner ring spring is formed by substantially circularly bending a strip spring so that both ends thereof are away from each other and the outer ring spring is formed by substantially circularly bending a strip spring so that both ends thereof are away from each other, the outer ring spring being fitted with the inner ring spring. Stoppers are provided in the vicinity of one ends of the inner and outer ring springs respectively. Each stopper is engaged with the other end of other ring spring, thereby holding one end side of each ring spring in such a condition that one end side of each ring spring is resiliently abutted against one end side of other ring spring.