A rotary spring-return actuator operator is provided with a multi-slot shaft and a clock type spring retained by a retaining band which encircles the spring in such a manner as to insure that the potential energy within the spring is safely contained during all operations requiring disassembly of the actuator assembly, and wherein the retaining band facilitates the in-field reversal of the spring direction or the adjustment of the spring preload by securing the spring to one or more of the slots on the multi-slot shaft.