Vacuum valve

A vacuum valve comprising:

• a vacuum vessel having an interior portion sealed by a fixed-end end plate and a moving-end end plate disposed at first and second end portions, respectively, of a cylindrical electrically-insulating tube;
• a fixed electrode rod secured to said fixed-end end plate, a fixed electrode being disposed on an end portion of said fixed electrode rod;
• a movable electrode rod, a movable electrode capable of contacting and separating from said fixed electrode being disposed on an end portion of said movable electrode rod;
• and
• a fixed-end shield secured to said fixed-end end plate and enveloping said fixed electrode and said movable electrode, said fixed-end shield preventing an inner wall surface of said electrically-insulating tube from being polluted by a metallic vapor generated by said fixed electrode and said movable electrode during electric-current interruption,
• a recess portion being formed in a central portion of only a contact surface of said fixed electrode.

A vacuum valve comprising:

• a vacuum vessel having an interior portion sealed by a fixed-end end plate and a moving-end end plate disposed at first and second end portions, respectively, of a cylindrical electrically-insulating tube;
• a fixed electrode rod secured to said fixed-end end plate, a fixed electrode being disposed on an end portion of said fixed electrode rod;
• a movable electrode rod, a movable electrode capable of contacting and separating from said fixed electrode being disposed on an end portion of said movable electrode rod;
• and
• a moving-end shield secured to said moving-end end plate and enveloping said fixed electrode and said movable electrode, said moving-end shield preventing an inner wall surface of said electrically-insulating tube from being polluted by a metallic vapor generated by said fixed electrode and said movable electrode during electric-current interruption,
• a recess portion being formed in a central portion of only a contact surface of said movable electrode.