Abstract: An actuator mechanism that decreases the time needed to move the contacts of a circuit interrupter between a closed circuit position and an open circuit position to reduce the probability of the occurrence of restrikes. The actuator mechanism uses a toggle spring arrangement that uses a single spring to move the interrupter through both an opening stroke and a closing stroke. The interrupter is designed to connect to the circuit in parallel, so that the interrupter is not normally in the circuit when the circuit is closed. Because the interrupter is not normally in the circuit, it can be manufactured to less stringent standards than those that apply to electrical components that normally remain in the circuit. The interrupter is well adapted for use as a puffer-type interrupter in which the contacts of the interrupter are contained in an arc-extinguishing gas, such as sulphur-hexaflouride (SF6) gas to further reduce the probability of restrikes and to minimize the effect of occurring restrikes.