Abstract: A transformer tap changing switch including a rotary contactor shaft supporting spaced apart radially extending arms having roller contactor sets mounted thereon and yieldably biased into engagement with adjacent ones of an array of elongated cylindrical rod contacts supported between spaced apart switch frame plates. Each of the rod contacts includes a centrally disposed lug or blade type terminal located between the roller contactor assemblies and spaced sufficiently from each such that current flow along the rod contact elements between the terminal portions and the rotary switch contactors establish counteracting magnetic force fields which substantially cancel each other and eliminate any forces acting on the rotary contactor assembly. The switch includes a manually actuated lever for rotating the contactor shaft and which is provided with a switch position locking mechanism including a spring biased pin which projects into a selected hole in a position locking plate member.

Abstract: A protective fuse comprising a fusible element disposed within an enclosure formed by a gas generating fiber tube connected at one end to a conductor rod and at the other end to an arc intercepting member. The arc intercepting member is connected to an elongated tubular resistor element which in turn is connected at its opposite end to a cap comprising a conductor connected to the fusible element. Upon parting of the fusible element an arc established by the fault current comes into contact with the arc intercepting member so that a circuit is established through the resistor element thereby momentarily reducing the fault current to a level which can be extinguished by the deionizing gases generated within the interior of the fuse. The conductor rod is formed of a magnetic material which is capable of generating a substantial magnetic flux which functions to bias the arc against the interior wall of the fiber tube to enhance the generation of deionizing gases.