Load switch for a step transformer

A switching system for a step transformer having at least two adjacent taps and a pair of terminals shiftable between the taps, the system comprising:

• a support;
• a pair of fixed contacts normally connected to the terminals and fixed on the support;
• a vacuum interrupter on the support connected between the terminals and displaceable between an open-circuit position and a closed-circuit position;
• a pair of movable contacts on the support each engageable with a respective one of the fixed contacts and forming therewith a respective bypass switch;
• a cam rotatable about a cam axis and having a contact face and an axially oppositely facing interrupter face each formed with a respective operating formation;
• drive means for rotating the cam about its axis through steps of a half revolution;
• means including a respective cam follower engaged between each of the movable contacts and the contact-face formation for opening and closing one of the bypass switches on rotation of the cam through a half revolution and for thereafter opening and closing the other of the bypass switches on rotation of the cam through a succeeding half revolution;
• and
• means including a cam follower and a force storer engaged between the interrupter and the interrupter-face formation for snapping the interrupter open and then snapping the interrupter closed each time the cam is rotated through a half revolution.