Low voltage vacuum switch with three internal contacts including a center floating contact

Abstract From the Canadian patent

A low voltage high continuous current dc vacuum, switch has at least three internal contacts including an, electrically floating center contact and two movable end contacts. The multiple contacts provide electrically serial multiple arc paths so that the switch is operable to interrupt an arc at a dc arc voltage above the arc voltages at which an arc could otherwise be interrupted for a single arc path. Arc shield means are provided to prevent deposition of contact material on predetermined switch envelope internal surfaces.