On-load tap changer switch assembly

Claim 1

On-load tap changer for a transformer having a base winding and a regulating winding, comprising: a diverter switch having at least two fixed contacts; a step selector having a plurality of fixed contacts connected to taps on said regulating winding and cooperating with two movable contacts, said movable contacts being mounted on two rotatable drive shafts and connected to the fixed contacts of said diverter switch; a drive mechanism connected to the drive shafts of said step selector for rotating the shafts in steps relative to each other; a plus/minus or coarse/fine switch connecting said regulating winding to said base winding; and a damping switch for temporarily during a plus/minus or a coarse/fine switching operation connecting said regulating winding through a damping resistor to a point of defined potential, said damping switch having cooperating fixed and movable contacts and comprising operating means including a cam member, said cam member being fixedly mounted on one of the drive shafts of said step selector and operatively connected to said movable damping switch contacts.