Abstract: A force-storing actuator for connection to a rotor of a step transformer has a pair of similar levers rotatable about a common axis and having diametrally opposite outer ends, an input element and an output element rotatable about the axis and operatively engageable with the levers, and a latch device for releasably retaining the output element in any of a plurality of angularly offset positions. Respective springs each have one end connected to a respective end of one of the levers and an opposite end connected to a respective end of the other lever and having a middle between the ends. Respective guides movable freely angularly about the axis between the lever ends at generally the same radial spacing from the axis as the lever ends are connected to the middles of the respective springs. Thus the springs each have a pair of sections flanking the respective guide and extending generally tangentially of a circle centered on the axis from the respective spring ends to the respective spring middles.