Abstract: A tap-changer vacuum switch having an actuating rod extending and displaceable along an axis is provided with a damper having a damper housing offset from and fixed relative to the vacuum switch, and a rod piston fixed on the valve-actuating rod, in the damper housing, and defining in the damper housing a compartment whose volume changes as the rod piston moves axially with the rod. The damper housing is formed with a pair of radially open ports opening into the compartment. An in-only check valve fitted to one of the ports only permits fluid flow into the compartment, and an out-only check valve fitted to the other port only permits fluid flow out of the compartment.

Abstract: A tap changer has a bypass switch with a rotary pair of movable contacts engaging arc segmental fixed contacts of a length greater than the spacing between the movable contact which spacing is greater than the spacing between the fixed contacts of the bypass switch.

Abstract: A multiphase reactor-switching tap selector has a single geneva mechanism operating three shafts which traverse phase plates carrying all of the contacts and the vacuum switching cell and rapid release mechanism for each of the phases. The geneva mechanism operates the tap selection contacts directly through its shaft and is coupled to other shafts for operating the preseslector contacts, the bypass contacts and the vacuum switching cells. All three shafts traverse all of the phase plates.