Patent ID: 7642478

Claim:
An apparatus configured to open and close an electric power cut-off device, the apparatus comprising: a motor; a crank assembly rotatable about an axis, wherein operation of the motor causes rotation of the crank assembly about the axis; a connecting rod having a first end and a second end, the connecting rod coupled to the crank assembly proximal to the first end, wherein rotation of the crank assembly causes rotational and translational movement of the connecting rod between a first position and a second position; a first stationary spring abutment positioned a first distance from the crank assembly; a second stationary spring abutment position a second distance from the crank assembly, wherein the second distance is greater than the first distance, wherein the first and second spring abutments are stationary with respect to the connecting rod; a mobile element coupled to the connecting rod proximal to the second end and moveable between the first and second stationary spring abutments, the mobile element coupled to the first stationary spring abutment via a first pre-stressed spring and coupled to the second stationary spring abutment via a pre-stressed second spring, at least the first spring configured to urge the connecting rod toward the first position, wherein movement of the connecting rod past a predetermined dead centre position between the first and second position causes at least the first spring to then urge the connecting rod toward the second position.