Described is a spring mechanism. The spring mechanism includes a leaf spring housing with leaf springs radially disposed within the leaf spring housing. The leaf springs being flexible between a rest state and tension state. A winding mechanism is engaged with the leaf springs for causing the leaf springs to flex from the rest state to the tension state. The winding mechanism includes a pushing pin wheel with a plurality of pushing pins protruding therefrom that rest against the leaf springs. The pushing pin wheel is rotatable such that rotation of the pushing pin wheel causes the leaf springs to flex from the rest state to a tension state. Release of the tension (i.e., when the leaf springs return to the rest state from the tension state) causes rotation of the leaf spring housing, which causes rotation of a corresponding release gear set and output drive.