wherein the break is in gas (in air at atmospheric pressure H01H33/77)

Full Title

High-tension or heavy-current switches with arc-extinguishing or arc-preventing means > Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid > wherein arc-extinguishing gas is evolved from stationary parts; Selection of material therefor > wherein the break is in gas (in air at atmospheric pressure H01H33/77)