BORIC ACID EXPULSION FUSE

摘要

A high voltage circuit interrupter characterized by a tubular insulating casing that encloses a tube of boric acid forming an elongated bore. The bore includes bore portions of smaller and larger diameter. An elongated conductor is disposed in the bore and forms a clearance space therewith. Fusible means extend between the enlarged conductor and a fuse terminal. Upon fusion of the fusible means the larger end portion of the conductor is retracted into the smaller bore portion while maintaining a clearance space therewith, so that a minimal clearance space between the smaller bore portion and the enlarged end portion of the conductor provides adequately high water vapor pressure to extinguish an electric arc generated by fusion of the fusible means.