Vacuum switching apparatus

A vacuum switching apparatus comprising:

• a fixed electrode and
• a movable electrode mounted in a vacuum vessel;
• said movable electrode being mounted in said vacuum vessel by means of a bellows surrounding and insulating rod connected to said movable electrode;
• said movable electrode being movable between a closing position Y1 and an opening position Y2 wherein a current between said stationary electrode and said movable electrode is broken and between said opening position Y2 and a disconnecting position Y3, and wherein said movable electrode is stationary only when at said closing position Y1 and when at said disconnecting position Y3;
• a means for bringing said movable electrode into contact with said fixed electrode or separating said movable electrode from said fixed electrode;
• and
• a deceleration means for controlling a speed of said movable electrode during movement from said opening position Y2 to said disconnecting position Y3 to be less than a speed of said movable electrode during movement from said closing position Y1 to said opening position Y2;
• and
• wherein a between-electrode opening distance D.sub.2 between said fixed electrode and said movable electrode at said opening position Y2 and a between-electrode opening distance D.sub.3 between said fixed electrode and said movable electrode at said disconnecting position Y3 satisfy a relationship of
• 0.5.times.D.sub.3 .ltoreq.D.sub.2 .ltoreq.0.7.times.D.sub.3.
• 3.

A vacuum switching apparatus comprising:

• a fixed electrode provided in a vacuum vessel;
• A movable electrode mounted in said vacuum vessel by means of a bellows surrounding a movable electrode connected to an operatng mechanism, wherein said movable electrode is moved between a closing position Y1 and a disconnecting position Y3, and stops only at said closing position Y1 and said disconnecting position Y3;
• the operating mechanism bringing said movable electrode into contact with said fixed electrode or separating said movable electrode from said fixed electrode;
• and
• a decelerating means which starts deceleration of a moving electrode at an opening position Y2 where a current between said stationary electrode and said moving electrode is broken and continues deceleration until said disconnecting position Y3, and
• wherein a between-electrode opening distance D3 between said opening Y2 and said closing position Y1 is not smaller than 0.5.times.D3, wherein D3 is a between-electrode distance at said disconnecting position Y3.