Abstract: A vacuum switch includes a mechanism for opening and closing the contacts including a drive link, three toggle links and a drop link. The drive link is coupled to the movable contact of the vacuum bottle and to a mounting tower. The drive link is also coupled to two of the toggle links. The toggle links are coupled to the drop link, which is in turn coupled to a lever. A cam is coupled to the lever via a pin. The cam is also coupled to an over-center spring mechanism. A handle is used to rotate the pin to which the cam is coupled, which in turn rotates the cam. As the cam rotates, the spring mechanism prevents movement of the lever and various links until a predetermined amount of energy is stored in the spring. When this energy level is reached, the spring assembly pivots, thereby allowing the cam to pivot as well. The pivoting cam strikes the lever and causes it to move. The lever in turn imparts motion to the drive system via the drop link.