Medium voltage switching apparatus

A switching apparatus for medium voltage electric systems, said switching apparatus comprising one or more electric poles, wherein, for each of said one or more electric poles, said switching apparatus comprises:

• a first pole terminal, a second pole terminal, and a ground terminal, said first pole terminal electrically couplable with a first conductor of an electric line, said second pole terminal electrically couplable to a second conductor of said electric line, and said ground terminal electrically couplable to a grounding conductor;
• a first fixed contact member and a first movable contact member, said first fixed contact member electrically connected to said first pole terminal and including a first fixed contact, said first movable contact member electrically connected to said second pole terminal and including a first movable contact, said first movable contact member reversibly movable about a corresponding first rotation axis, so that said first movable contact can be coupled to or uncoupled from said first fixed contact or said ground terminal;
• a second fixed contact member and a second movable contact member, said second fixed contact member electrically connected to said first pole terminal and including a second fixed contact, said second movable contact member including a second movable contact and reversibly movable, along a corresponding translation axis, so that said second movable contact can be coupled to or uncoupled from said second fixed contact;
• and
• a vacuum chamber, in which said second fixed contact and said second movable contact are enclosed and can be coupled or decoupled;
• wherein, for each of said one or more electric poles, said switching apparatus comprises a motion transmission mechanism for actuating said second movable contact member, said motion transmission mechanism including:
• a cam member movable about a second rotation axis and coupled to said second movable contact member, wherein said cam member exerts on said second movable contact member actuation forces moving said second movable contact member along said corresponding translation axis, when said cam member rotates about said second rotation axis, wherein said cam member is electrically conductive and electrically connected to said second movable contact member;
• a first lever arm coupled to said cam member and extending radially with respect to said second rotation axis, wherein said first lever arm is electrically conductive and electrically connected to said second movable contact member;
• and
• a second lever arm coupled to said cam member and extending radially with respect to said second rotation axis and angularly spaced with respect to said first lever arm, wherein said second lever arm is made of electrically insulating material, and
• wherein said cam member is movable between a first switch position, which corresponds to a coupling position of said second movable contact member with said second fixed contact member, and a second switch position, which corresponds to a decoupled position of said second movable contact member from said second fixed contact member, upon actuation of said first lever arm or said second lever arm by said first movable contact member, during an opening maneuver or a closing maneuver of said switching apparatus.