SWITCH APPARATUS FOR CONNECTION WITH A DC CIRCUIT

A switch apparatus usable in a DC circuit employs a rotatable shaft having conductors that are removably connected with two or more pairs of contacts that are situated on line conductors and load conductors and that are connected in parallel by the conductors on the shaft. In rotating the shaft to open the switch, one pair of the contacts is electrically disconnected prior to electrical disconnection of the other pair of contacts. Further rotation of the shaft causes the other pair of contact to eventually become disconnected. Electrical arcs thus form only at the air gaps between the other pair of contacts and the conductor. Magnetic field elements in the form of permanent magnets are situated in the vicinity of the air gaps of only the other pair of contacts and apply Lorentz forces to the arcs to extinguish them.